-Refused to do a 3 million $ replacement -Killed a mother, spent 18 million $ in settlement, and still have to do the replacement after that I wonder how many corporate decisions ended up that way
Sadly, the strategy usually works, especially when you factor in that short-term incentives encourage rolling the dice on this being the next guy’s problem
Sadly, this type of short-term thinking happens all the time. It is particularly galling when lives are at stake. Lethality or not, those making the risk assessments are often not knowledgeable enough to assess the full complexity of the risk - it’s closer to a guess.
"Now, should we initiate a recall? Take the number of vehicles in the field, A, multiply by the probable rate of failure, B, multiply by the average out-of-court settlement, C. A times B times C equals X. If X is less than the cost of a recall, we don't do one."
Contract Glazier here, This video is awesome and explains my job of assembling the building envelope so well, and by one of my favorite youtubers! but a couple of notes: First, low e is rarely a film these days, now it is a coating applied to the glass just after the float process. second, Wind load is often miscalculated, and reduced to a simple "wind factor" for different jurisdictions that doesn't actually give enough information to us glaziers to determine if thicker or laminated glass is required. third, 99.99% of modern buildings are glazed with 1" IG units consisting clear tempered glass. many times, a cracked window is brushed off as it is on the outer lite and therefore the resident or tenant will feel its ok so long as outside air isn't getting inside. Fourth, heat strengthened glass is no longer standard, and sometimes even not code. Nowadays, if you want stronger glass, you purchase what is called heat soaked tempered glass, which is standard tempered glass that is "soaked" in a heated oven, and will break roughly 50% of the panels and the panels that survive are rated to only break 1/100,000 times. Fifth, EVA is being removed in many cases for its ability to absorb moisture. PVB on the other hand does not have this down side. SGP is also used as a lamination layer where structure is needed as it is a stiff interlayer allowing the glass to remain in place and in shape once the individual lites have burst. Sixth, $3,000,000 is a 1990 price for the replacement for sure, modern glaziers would charge closer to 26,000,000 to replace all the glass in the CNA building with current safety and energy standards. Lastly, many of these standards and safety requirements are not looked at by the owner or contractors, the ARCHITECHT dictates their standards and specifications for the building, and if they dont spec the safest material, we as contractors wont price the safest material, as we don't want to lose the bid to a company that doesn't care since safety has an additional cost, so while we do care, we can't do much other than plead with the general contractor to plead with the architect.
Reading more about the story, it was in 1996 when CNA got the replacement cost estimate of $3,500,000 (the spending power equivalent of $7,000,000 today) with the tragedy occuring in 1999 and a $18,000,000 settlement paid out to the family in 2002 and an additional ~$500,000 paid in settlement with the city which included $250,000 in fines. So in 2002 they paid out a total of approximately $18,500,000, and while adjusting for inflation that would be ~$34,230,698 today. Kinda insane to think about just how much all those safety requirements and measure might have driven up the cost of replacement and installation of windows between 1996 and 2024, but even still would be a bargain compared to how much it would cost to payout settlements for any wrongful "endings" lawsuits that could result in not investing in doing the right thing. $26M to replace vs $34M+ in settlements and legal fees.
Building thermal engineer here. Low E glass films and coatings don't change the radiated heat absorbed from sunlight. They change the conductive heat transfer, so that the wind doesn't pull heat through the glass as easily. Regular tints absorb light rather than letting it through the glass, and mirror tints reflect that light rather than absorbing it. So a mirror tint is the only thing which will reduce the heating of the glass itself.
Former glass tempering furnace operator here. Tempering low-E isn't much different than tempering clear glass of the same thickness. Tempering tinted is faster. Glass with the Solarban/Sunguard coatings based on indium tin oxide are different. They take much longer to process and are more likely to break or bow, sometimes ending up in the quench pans, sometimes after it appears to be fine, and breaks sometime after it's placed in the harp racks, and worst of all, cracking in the furnace.
@@CatsCatsCats-qs6cxso I don't know but to me it seems obvious stick on the outside the same thing people use as screen protectors so that if the glass does crack its atleast still held together to be replaced rather then displaced and not like the film that was talked about but a thin sapphire or plexiglass one as a thin sheet and it will also take on some of the heat instead of the window alone and maybe they can get one with a coating that will reduce heat it would be cheaper then buying the whole window with that sort of effect and unlike the laminated glass if water gets in between this and the window it can be pushed out like with window tint
I am impressed that he was willing to stand under that precarious tower. Imagine the headline: "Architect Struck By Falling Glass While Making A Documentary About Falling Glass."
Even if a tempered glass was more likely to fall out when breaking, it still feels safer to have a higher probability of minor injury vs a lower probability of serious injury or potential death. Minimizing catastrophe (like the tragic death of the mom) feels more important than minimizing injury. We need to consider failure modes in addition to failure likelihoods. That film worsens the failure mode and should never have been considered.
@@renatanovato9460 wind resistance is significant for small objects. height isnt that big of a deal. example: dropping a penny off the empire state building never actually hits the ground. as long as it's not shaped like an arrow or a bullet (aerodynamic) or really big, it should be fine. at the very least, way way better. edit: i forgot that the mass is actually a pretty major point too. myth busters shot pennies at 65mph and they were unable to penetrate anything because their mass was so low. less mass means less momentum (even at high speeds) which means less transfer of energy and less impact.
@@gonelucid Yes. The classic "penny off the Empire State Building will kill you" Pennies dropped off the Empire State Building just get blown onto the floors below. This is what I was referring to. It's besides the point though, even if they did hit you they'd still only cause minor injury. Same with tiny balls of glass from tempered glass shattering.
I went to college in Boston in the mid 1970s. When I moved there, the John Hancock Tower in Copley Square had just been completed after terrific problems with its glass curtain wall. About half of the building's glass had popped out and fallen to the street during construction. For years most of the tower's facade was covered in plywood panels. People joked that it was "the tallest wooden building in the world." By the time I moved to Boston all the glass panels had been replaced, but the memories were still very fresh. While the original glass was a major part of the problem, it turned out that the building was oscillating in the wind far more than anticipated, which contributed to the problems with the glass. The building needed to be structurally reinforced, at great cost. Fortunately, it hadn't been occupied yet, but as a result the opening was delayed by about four years. It is a beautiful feat of architectural sculpture, due to its shape and reflective glass. From certain vantage points ot practically disappears or seems like a two-dimensional cutout on the skyline. From the structural point of view, it was a powerful and very expensive object lesson in engineering hubris.
@brunodesrosiers266 Replacing the whole curtain wall system makes perfect sense to me. When I tried to find out exactly what had gone wrong I kept running into nondisclosure agreements made in response to lawsuits, but this was many decades ago and I don't know whether those agreements are still in effect. Despite the colossal failure, it didn't seem to affect IM Pei's (the architect's) practice too badly.
It was a mess. The city had to close the streets for blocks around when the wind blew. After the the original windows were replaced, you could find used John Hancock windows in resale shops throughout New England. I saw some.
The New York sidewalk "sheds" aren't there semi-permanently either because they're needed for inspections (they aren't) or because they'd be expensive to remove. Instead each one represents an instance where a potentially dangerous façade has been identified by inspection and so the protective shed mandated but it's much less expensive to pay the fines imposed by Local Law 11 - not revised since it was introduced - annually for not doing the repair than it would be to repair the building. If the city would just update it's schedules of fines in line with inflation more repairs would be done and so more sheds taken away. Just another example of New Cork City's love of incompetent governance.
It makes so much sense now. Last time I visited NYC, like 50% of the sidewalks were covered by these scaffolds. I had no clue I was walking under a potential death trap that building owners don't feel like fixing. Now I understand why people don't want to live in NYC anymore.
.....in the long term. The problem is a short-term profit mindset, especially among geezer executives who won't be around to deal with the long-term consequences of going cheap.
Even the cheaper solution would've been fine in this case, as it gave them ample warning time, if they had bothered to immediately replace any cracked windows held in place by the film instead of letting them sit there for months until it failed.
Economic principles like present values tell us that profit motivated people will always choose money now over money in the future. Save money now by cutting costs means investing and growing that money for the firm to have more later so much more later that it's worth ignoring dangerous faulty designs because it's worth taking the risk that something could maybe happen later on and just paying the legal fees to deal with it. Something did happen? This is fine legal fees will be paid for with returns made off capital that was invested instead of being spent on repairs.
@@wheeliebeast7679its not they wont be around its that it is more profitable to invest that money instead of repairing things. Just take some of the returns on that investment to cover any legal liability that might happen in the future.
Wow for most of this video, I didn't think the building owner was _that_ negligent. But then when he said that the window that fell and killed someone _had_ the film on it and just was put off and pushed down the list of repairs really changed it for me. Can you imagine being one of their family members? The building is freaking red so it catches your eye. I bet every time they see it, it brings back some part of the pain from losing them. It's ironic too that it would be a red building. It's almost like they have been warning people to stay away since the beginning because red often means danger
The loss of windows at the Sears Tower came from failures in the outer skin of the glass. Slag from welding on higher floors scarred the glass below allowing it to fail.
As a Son of Contruction workers n welders that’s sad They know their work Is suppose to test time my father in law 70 years old when we ride around the city we see atonnof building he set 30-40 years ago standing strong
The Bernoulli effect may not be a commonly understood concept, but pretty much everyone in Chicago gets it on practically an instinctual level. Walking around a tall building between the high pressure and leeward sides allows you to experience the effect firsthand - watch as people brace themselves as they enter the low pressure zone and also pay attention to where the smokers gather (lol).
I'm surprised that even after all this time most Windy City towers are still incredibly blocky. You'd think given the stresses put on them more Marina City-style buildings would have risen... Alas...
Canada's tallest tower outside of Toronto, the 251m tall Stantec Tower, in Edmonton has been notorious for his shiny glass facade cracking and smashing into the ground below ever since it was opened back in 2018... For a while there was a pane a month falling from the tower it seemed. While it may not have been that bad it did kill all semblance of pedestrian traffic in the area and as a result a lot of the development in the surrounding ICE District has failed to flourish. Food hall? Still just a shell 6 years later. Cinema complex? Scrapped. Pharmacy? Shuttered after less than a year in business... I know I've only been to it twice or thrice since it opened and I basically sprinted through the plaza on the way to the arena. Maybe there's something to be said for more traditional facade materials besides wafers of melted sand...
Be very careful, a lot of cars produced 2018 or 2020 and later now often have front side laminate windows. Look for information near the bottom right of the window, look at all 4 of your windows. This was due to federal requirements on ejection / limbs outside vehicle in rollovers. So those escape / safety tools no longer work on laminate, they just cause a small crack.
Yes thank you. This guy calls it tempered glass when it’s laminated glass. Makes me wonder how much else he got wrong if he can’t get the windshield glass correct.
The 32 story Anthony J. Celebrezze federal building in Cleveland, Ohio, built in 1967, had issues with glass falling out. Moisture was being trapped inside and minor repairs had been done throughout the decades as quick fixes. But due to growing issues with safety and energy costs, something major had to be done, without disturbing the daily activities of the tenants. So, the entire building was wrapped with a new curtain wall of windows outside the existing windows. This was completed in 2015 for about $120 million. It looks like a brand new building now, but if you look closely you can still see the original windows behind the new facade.
Safety is as good a reason as any for that kind of project. I live near a downtown building that was enclosed that way in the 1950s; from a distance, it looked like a giant trailer stuck between two masonry buildings. About 40 years ago, they peeled off the cladding system and revealed a handsome Victorian-era brick building I had never seen before. I've seen stories about other old buildings covered up the same way when their style went out of fashion, then uncovered as fashions changed again.
omg. When you're hear that the falling pane was one of the "repaired," windows, you can't help but feel your stomach drop. There have been a number of pieces of glass fall here (Calgary) but to my knowledge, no one has been killed. We are in an area with extreme winds similar to Chicago: it's not unusual to have 60mph straight line winds once or twice a year, and every year has many days with 50mph winds. As far as I know, that's at the surface; I'm not sure what it is in high rises. I believe many condo buildings have bylaws regarding securing things on their balconies. I'd be very curious what they've done with the fenestration here regarding heat treatments, because we also have a huge diurnal variation in temperature. Sunny days can rise from 32F to 70F air temperature, and I'm not sure what that would translate to for glass surface temps in the sun.
And that's why the wind is so bad in Chicago because you've got all different shapes of buildings and that wind is coming off the lake like nobody's business
Aeon Tower's twin in Toronto (First Canadian Place - it's the same building, but with the windows oriented horizontally rather than vertically) had a similar problem - one of its Carrera marble slabs fell off the facade in 2007, with many more at risk to do the same. The marble was removed, and the facade replaced, in the early 2010s - primarily with white glass tiles. Cost was CDN$130 million (US$96 million).
My favorite channel! Please do a video on how to transform bankrupted and empty neighborhoods… In Detroit we have whole neighborhoods that are empty and poor with thousands of abandoned homes and empty lots. How can the people of the city rebuild it? Is gentrification inevitable? Are there examples of a local population taking advantage of that situation and improving their conditions? How would an architect approach the problem or even think about it?
These are questions more centered around City Planning than Stewart usually covers and specializes in, but I too would very much like to see this video. There’s not going to be an easy answer. Maybe Canada can buy it 😅
'New urbanist' planners have extensive experience with this, and have accumulated a lot of knowledge about making safe, interesting places that will endure and inspire. Mixed-use zoning and code reform are critical for the activation of lively, walkable streets, to foster individual entrepreneurial opportunities, and to enable long-term economic viability. Housing and employment options for residents of varying income, age and social strata are essential to maintain a thriving community, whether old or new. The availability of financing and insurance for such development must be secured, as well as the approval of government administrators, utility providers, fire protection districts and traffic engineers, among others. Certain levels of density, porosity and interconnection are necessary to ensure convenience and efficient mobility. Consideration must also be given to the need for outdoor public spaces and recreation, schools and civic institutions, restaurants, bars and coffee shops, retail areas and entertainment venues. Good planning work involves reviving and integrating successful development patterns from the past with the functional needs, values and aspirations of local modern life. The Congress for New Urbanism (CNU) promotes and supports these principles, and they're having a significant influence on planning policy in North America and elsewhere. Many architectural and planning firms now specialize in this field, and a wide range of beautiful and useful books have appeared in recent years. There are also numerous informative lectures on TH-cam, from CNU members and others. If you're interested, look for talks by Andres Duany, Jeff Speck, Victor Dover, Leon Krier, and Stefanos Polyzoides for a start, and for the work of firms such as DPZ, Dover Kohl and Placemakers.
Fascinating video! Would it be possible for you to do a video on the challenges of converting old office buildings into housing? That seems to be gettin a lot of steam lately
Imagine just walking down the sidewalk and seeing a guy talking to a camera about windows crashing down from the very building you're walking by, killing pedestrians
Most instructive. In addition to giving me an insight into the principles and practice of glazing tall buildings, this vid taught me that cost:benefit analyses are fundamentally flawed.
Stewart, do you have any recommendations for any books related to some of the topics you cover? I have been really enjoying your videos and would like to learn more
Keeps happening in Manchester UK too. Even some blocks of apartments with just a dozen floors have been completely covered in enormous stretchy nets for over 2 years to stop anything falling on pedestrians. All the residents have these ugly nets across their windows.
Slight correction on the car comparison. Windshields are laminated you even showed a pic of it. Side & rear windows are tempered and will shatter into little pieces
Moderne cars are starting use laminated glass on the side windows. Tempered glass has been found to be a potential risk for side airbags while laminate mitigates that risk.
I worked on the recladding the Aon Center in the 1980s (at the time it was the Amoco building). I was in my 20s and wasn't licensed yet. Definitely an educational experience.
i have a constant if quite minor fear of this happening to me every time i walk around Chicago or any other city with tall buildings and this does not help me haha
I LOVE videos like this with more building science in them! The relationship between the art & engineering halves of architecture is not commonly talked about, at least that I've seen on TH-cam.
In an extreme case of shedding glass and building parts: I was in Houston in 1983 after hurricane Alicia. The streets were covered in broken glass shards and metal facade parts. There was glass embedded in wood and dirt. One literally could not have survived being anywhere between buildings. Roof gravel had blow off of badly maintained roofs and broken windows that might have otherwise survived. It was not like the total loss of structures like the tornadoes I've seen, but it's the next worst thing.
This may be a dumb question, but why don't they just install the windows from the inside instead, make the casings surround the exterior of the window more, and allow an interior gap to give the window some expansion room? That way, if they do fall, they'll fall inside. And I know, they could still kill someone or seriously injure them, but it just seems like it would be easier to deal with that way.
I was working in the CNA building that day. On the 5th floor at Mack and Parker an insurance company. It was very sad when this happened. The kid was just trying to wake the mom up until a bystander grabbed the kid.
I've worked in many high rises. In most of them, the windows were 20-40 years old and were still holding up well. Never encountered a broken window. Then we built one building about 12 years ago and have spontaneously lost about 30 windows to shattering over the years. Mostly ground floor windows but some at higher levels. We were quick to blame vandalism but have ruled that out. We never have come up with an adequate explanation, other than this is the first building constructed with Chinese made glass which may be of a lower quality.
2:55 This building used to be the headquarters for Bank of America. It was the tallest building in the city when it was built. I remember looking down at the street below and momentarily thinking that the window in front of me might pop out. Apparently, the thought had some validity.
How could architects, who should know about material science, choose marble over granite not knowing of the probable outcome? Was anyone called out over the decision?
I'm an engineer. These decisions are always aesthetic after financial. You change materials when the owner can't afford it. If you say it can't be done, they hire another firm. Longevity is a future problem that doesn't exist for construction management or the list of temporary owners.
Famous marble buildings include the Taj Mahal, Supreme Court, and Lincoln Memorial. It's a very common building material. The problem on this building may have been using it in thinner sheets, which then had problems. There is a challenge in materials science where manufacturers are always coming up with cheaper solutions, and sometimes it takes a few years before the problems with the new material or approach become known.
@@MTBSPD Don't they make panels of more flexible materials like cement-board, with thin marble veneer glued to it? I'd think that if they used the right cement, that would keep very much of the surface from chipping off at one time.
Because they are architects, not engineers. Their primary goals are how good it looks and how usable it is. Even tho they do need engineering skills, they are limited, compared to those of an actual engineer. And both tend to work together on projects. It's not that architects need more engineering knowledge. It's that people in charge need to consult with engineers and not gamble with risks.
1:48 the shadowed glass does not remain the same temperature, it warms through conduction, albeit very slowly. the expansion does not occur with a discontinuity, but a significant differential
Not even joking, I almost got hit by an 8 inch very floppy, just recently used dildo thrown out of a window of an apartment building in Manhattan. The reason why I knew it was just used a couple of minutes before is because as it landed on the pavement, it was completely glistening in female body fluids. I looked up and for a split second saw two people pop their smiling heads out of their balcony ledge and pop back in when they noticed me looking up. I wasn't too amused, but I can imagine they were laughing hysterically, which is exactly how I would have reacted if I almost hit someone on the head with a glistening and dripping moist dildo from my apartment balcony. I just kept walking cus that isn't even in my top 20 of the weirdest shit I've experienced in NYC.
Sheesh, a mom being struck by a huge slice of glass right next to her kid sounds like a scene straight from a slasher horror movie. I wonder how much of those 18 millions go straight to therapy over the years.
I love all the gorgeous shots of the Chicago skyline you include- our city has such beautiful architecture, and your videos are not only informative but visually very pleasing to watch :)
They will need to modify those little sidewalk signs from 'Caution Falling Ice' to 'Caution Falling Ice/Windows/Facade'. That should solve the problem.
Not the stuff of your typical "architectural tour" A bit technical but required viewing for anyone who lives and works in -or merely visits- a skyscraper district. A cautionary tale and literally a matter of life and death -and, for those to whom it matters, dollars. Worthwhile and well done.
10:55 They shouldn't be prototypes, except for in the vaguest sense. These are buildings, not toys. They can and do kill many people. I think you should treat the fact the fact that these buildings killed people much more seriously than you did in this video. It could have been you.
Awesome video, earned my subscription! I was interested just from the thumbnail, little did I know it was about an incident I didn't know about in front of a building I used to pass daily! Love the style and insights. Thank you
Thanks Steward, a very important video. Simple and highly informative! The problem is going to become increasingly important due to to Klima change. Very few of our Ingenieurs are looking in to the consequences of the difference between our models and the reality we are already experiencing. The problem is particularly pronounced with listed modernist buildings here in Scandinavia where there are strict requirements to preserve geometry and, not least, relief. As you say, it is extremely important to be aware of the solar influence on the glas by even a modest relief effect and the resulting tensions. The pressure differences are an equally important factor, I am there where technically you might have to handle the facades more individually than we do now. Jesper from Copenhagen
It's easy to look at what the right decision is in hindsight, but at the time, they were probably trying to figure out where they could pull 300k from, let alone consider 3 million.
Now if only they would stop making skyscrapers that are just giant rectangles clad in a glass facades, modern skyscrapers seem to just be worse in every way with these designs, they are bland and ugly, glass facades frequently falling off, and they are harder to actually heat and cool vs old buildings.
Are they really less efficient versus old buildings? Seems like that's not necessarily true due to the way modern energy standards have been applied for at least the past decade, if not longer. Cite references please.
The only problem with that is most of the time is spent in the building, where it's a lot nicer to look out floor to ceiling windows that let in much more natural light which boosts mood and energy. Smaller windowed buildings with classic designs can be much more appealing from the outside but much less enjoyable on the inside.
Stay in a room with floor to ceiling windows for a night and try to tell me that it isn’t an extremely desirable design feature. Also, I doubt that’s even the primary issue, the problem with Aon Center wasn’t even the glass at all, plus Aon and CNA are both over 50 years old, with much less glass on their facades than most modern skyscrapers.
I dont mind a lot of glass, but if there is too much, like covering the entire thing, i dont like it. Add like a strip of decorative metal or something.
Agreed. These hulking glass towers are butt ugly and good at nothing. And they’re unpleasant because the floor to ceiling glass makes it feel like you’re going to fall through the window.
By far the best and one of the cheapest way to strengthen glass is by using a potassium salts treatment to reoganize the glass molucule structure. Makes glass over 15x stronger than regular tempered glass. It was invented during the 50s in east germany because of a glass shortage. After that glass shortage it has never really been used again up until recently: it's often used for things like smartphones where it's called "gorilla glass". Because production of that chemically treated glass has been basically 0 for half a century, production facilities for larger pieces still don't exist yet...
In towers tall, where dreams ascend, Glass windows gleam, a skyward trend. Yet amid the heights, a flaw unfurls, A strange affliction, a plight of worlds. The Weird Flaw Plaguing Skyscraper Windows, A tale of caution, where danger grows. From Chicago's CNA, the story's told, Of windows falling, a fear unfold. In design's embrace, they're set with care, But sometimes fate's whims, they cannot bear. Physics at play, a delicate dance, Where forces unseen, may wreak their chance. From towering heights, they meet the ground, With a shatter loud, a mournful sound. Why does this happen? Many inquire, As shards cascade, like tears of fire. In this video's realm, we delve deep, Exploring secrets, the reasons to keep. From stress to strain, and winds that blow, To flaws unseen, that silently grow. Prevention's key, a vigilant eye, To spot the signs before they fly. Structural checks, and laws in place, To safeguard lives in urban grace. So heed the lesson, this cautionary tale, As skyscrapers rise, and winds assail. For in the heart of each towering sight, Lies the weird flaw, lurking in the light.
The Chicago skyscraper architects should look into making the footprint of their skyscrapers that of *a parallelogram.* No matter which direction the wind blows from, you never get a “leeward” suction side.
The semi-permanent scaffolding thing is a weird predicament. On one hand, it's ugly all year round, but otherwise, you're actually protected from rain and falling debris. While living in Vancouver, where it's constantly raining, I always wished there were more overhead on the sidewalks.
First time I heard about the problem was from the pyramids on the north side of Indianapolis. The sloped side was all glass. As the temperature dropped. the panes shrank. Then, the glass would fall inside the building. It was a cost cutting measure that backfired after they had to replace all the glass on the south side of all 3 buildings.
Before I even hit the play button I was thinking CNA. Every time I walk by it I can’t help but think of all variables of that woman’s day that put her in that spot at that time.
In New York City I always feared those Gargoyles high on top of our buildings! People were killed by Gargoyles, stones etc. Don’t cities inspect these things regularly??? 😅 Heads-up! In-coming Gargoyle! 👹
Stewart, love your channel, super enjoy your love of architecture as I lived in "Chi town" for over nine years. The first fives years were with a CPA firm that seemed to include an invisible clause in my contract that I had to work only in 90+ story buildings! Summer: Sears Tower (don't care, I'll never call it by another name, no disrespect to "Willis") Winter: John Hancock Tower. Sadly, my roommate, another CPA worked in the CNA building and during the time of the accident you reference. So very sad... Even though I left being a CPA though a numbers person I love architecture and that which is in Chicago. However, given falling sheets of ice in the winter, breaking windows, falling sheets of marble (from the Amoco building, as I knew it back then). While this URL relates to a totally different subject, I believe it is applicable here given the starting point I want to include (5:01). th-cam.com/video/DutJLb-c0vs/w-d-xo.htmlsi=nagYrDyFMa7NKPb0&t=301. I appreciate the inspiration, but wake up! Stewart, I tend to visit Chicago in May & November. Careful, I might just reach out and hug ya! So appreciate the work! Just sayin'
Architects should be held liable for flawed building features. Maybe that way they will be more focus on sound building practices than winning self-serving awards. There is no excuse for windows falling out.
If I remember my history right, the Babylonian Codes of Hammurabi, one of the oldest written laws had death as punishment for builders whose structures caused death. And if their construction failed without any death they had to rebuild it with their own money.
Architects have little to no say in the final construction practices taken. The general contractor or engineer who signed off on the plan would ultimately be 1) considered fully or majorly to blame and 2) held fully or majorly responsible.
Every major city knows which buildings are the problem. I visit major cities in the USA and Canada and I am smart enough to know what side of the sidewalk to avoid. Typically each city has only 2 or 3 buildings that are a problem. Don't park your car or walk on the sidewalk under them!
Another vote for @Dysprosio2's request for including metric. Actually, you often do -- even in this video, for example, when at 7:35 you say ‘6 mm or ¼" thick pieces of glass…’ Building it into the script is kindest I suppose, but can get tiresome with lots of numbers, in which case just subtitles or perhaps flashing the metric equivalent on screen can help keep it simple for all. And it's often not a big problem - many people can picture common measurements such as the ¼" mentioned, for example, but might find pound-force per square inch as esoteric as pascals, and I easily understand that 165 lbs of force on windward windows is quite a lot smaller than the 1,000 lbs of suction force on the other side without the metric equivalents of 75 kg and 454 kg. But including metric really does help, rather like knowing a few phrases in a foreign language when on vacation.
Crazy. My mom worked for CNA for years out of Portland. She ended up leaving after my grandfather died to a company that treated her much better (even allowed her 2 weeks paid vacation right when she started, to handle gramp’s funeral arrangements and such).
The options should have been film the glass asap while replacing the most problematic windows with the new glass, ie the ones that break the most in the history of the building and the ones above the most walked pavement, until you can change all of them over time! Still not a defence for the tragedy that happened, but then it's an accident, not negligence.
“[This glass is really good at not falling out of the building and killing people, but it makes the sky look wavy when you look out through it, so we won’t use it]”.
Why don't we reduce the total number of windows, like modern skyscrapers is ridiculous with he amount of glass that basically totally cover the whole building. That would be less windows to worry about and less of a expense in the long run.
I lived in Sao Paulo for a while. In front of the building where I lived, they made a huge office tower with a glass facade. Once, during a wind storm, the glass panes started flying away. It was a wizard of Oz view. It is a totally different problem with similar results and most likely a similar source.
Buildings should be designed with aerodynamics in mind. Square buildings with sharp corners create all sorts of issues from increased urban heating and wind tunnel effects.
-Refused to do a 3 million $ replacement
-Killed a mother, spent 18 million $ in settlement, and still have to do the replacement after that
I wonder how many corporate decisions ended up that way
Sadly, the strategy usually works, especially when you factor in that short-term incentives encourage rolling the dice on this being the next guy’s problem
Sadly, this type of short-term thinking happens all the time. It is particularly galling when lives are at stake. Lethality or not, those making the risk assessments are often not knowledgeable enough to assess the full complexity of the risk - it’s closer to a guess.
"Now, should we initiate a recall? Take the number of vehicles in the field, A, multiply by the probable rate of failure, B, multiply by the average out-of-court settlement, C. A times B times C equals X. If X is less than the cost of a recall, we don't do one."
@@freetolook3727 why just Ford? They all do it.
All of them. Safety regulations are written in blood.
The irony of keeping up scaffolding (a non-permanent structure) permanently in the name of safe building facade inspections is not lost on me.
Contract Glazier here,
This video is awesome and explains my job of assembling the building envelope so well, and by one of my favorite youtubers! but a couple of notes:
First, low e is rarely a film these days, now it is a coating applied to the glass just after the float process.
second, Wind load is often miscalculated, and reduced to a simple "wind factor" for different jurisdictions that doesn't actually give enough information to us glaziers to determine if thicker or laminated glass is required.
third, 99.99% of modern buildings are glazed with 1" IG units consisting clear tempered glass. many times, a cracked window is brushed off as it is on the outer lite and therefore the resident or tenant will feel its ok so long as outside air isn't getting inside.
Fourth, heat strengthened glass is no longer standard, and sometimes even not code. Nowadays, if you want stronger glass, you purchase what is called heat soaked tempered glass, which is standard tempered glass that is "soaked" in a heated oven, and will break roughly 50% of the panels and the panels that survive are rated to only break 1/100,000 times.
Fifth, EVA is being removed in many cases for its ability to absorb moisture. PVB on the other hand does not have this down side. SGP is also used as a lamination layer where structure is needed as it is a stiff interlayer allowing the glass to remain in place and in shape once the individual lites have burst.
Sixth, $3,000,000 is a 1990 price for the replacement for sure, modern glaziers would charge closer to 26,000,000 to replace all the glass in the CNA building with current safety and energy standards.
Lastly, many of these standards and safety requirements are not looked at by the owner or contractors, the ARCHITECHT dictates their standards and specifications for the building, and if they dont spec the safest material, we as contractors wont price the safest material, as we don't want to lose the bid to a company that doesn't care since safety has an additional cost, so while we do care, we can't do much other than plead with the general contractor to plead with the architect.
Reading more about the story, it was in 1996 when CNA got the replacement cost estimate of $3,500,000 (the spending power equivalent of $7,000,000 today) with the tragedy occuring in 1999 and a $18,000,000 settlement paid out to the family in 2002 and an additional ~$500,000 paid in settlement with the city which included $250,000 in fines. So in 2002 they paid out a total of approximately $18,500,000, and while adjusting for inflation that would be ~$34,230,698 today.
Kinda insane to think about just how much all those safety requirements and measure might have driven up the cost of replacement and installation of windows between 1996 and 2024, but even still would be a bargain compared to how much it would cost to payout settlements for any wrongful "endings" lawsuits that could result in not investing in doing the right thing. $26M to replace vs $34M+ in settlements and legal fees.
Thanks for the detailed breakdown, that was quite informative!
+super good information thanks for adding in onto an already really interesting video/story
So the old glass that fell on the mother was thick single pane plate? If it was from 1975 it had to be something scary like that.
Thanks
Building thermal engineer here. Low E glass films and coatings don't change the radiated heat absorbed from sunlight. They change the conductive heat transfer, so that the wind doesn't pull heat through the glass as easily. Regular tints absorb light rather than letting it through the glass, and mirror tints reflect that light rather than absorbing it. So a mirror tint is the only thing which will reduce the heating of the glass itself.
Will that affect the temperature outside the building?
Cheers
Thanks for the info
Former glass tempering furnace operator here. Tempering low-E isn't much different than tempering clear glass of the same thickness. Tempering tinted is faster. Glass with the Solarban/Sunguard coatings based on indium tin oxide are different. They take much longer to process and are more likely to break or bow, sometimes ending up in the quench pans, sometimes after it appears to be fine, and breaks sometime after it's placed in the harp racks, and worst of all, cracking in the furnace.
@@CatsCatsCats-qs6cxso I don't know but to me it seems obvious stick on the outside the same thing people use as screen protectors so that if the glass does crack its atleast still held together to be replaced rather then displaced and not like the film that was talked about but a thin sapphire or plexiglass one as a thin sheet and it will also take on some of the heat instead of the window alone and maybe they can get one with a coating that will reduce heat it would be cheaper then buying the whole window with that sort of effect and unlike the laminated glass if water gets in between this and the window it can be pushed out like with window tint
I am impressed that he was willing to stand under that precarious tower. Imagine the headline: "Architect Struck By Falling Glass While Making A Documentary About Falling Glass."
He says in the video that they replaced all the windows...
Even if a tempered glass was more likely to fall out when breaking, it still feels safer to have a higher probability of minor injury vs a lower probability of serious injury or potential death. Minimizing catastrophe (like the tragic death of the mom) feels more important than minimizing injury. We need to consider failure modes in addition to failure likelihoods. That film worsens the failure mode and should never have been considered.
I don't know if it would be a minor injury given the height of the fall
@@renatanovato9460 wind resistance is significant for small objects. height isnt that big of a deal. example: dropping a penny off the empire state building never actually hits the ground. as long as it's not shaped like an arrow or a bullet (aerodynamic) or really big, it should be fine. at the very least, way way better.
edit: i forgot that the mass is actually a pretty major point too. myth busters shot pennies at 65mph and they were unable to penetrate anything because their mass was so low. less mass means less momentum (even at high speeds) which means less transfer of energy and less impact.
@@renatanovato9460 As someone who has been hailed on: It would feel a lot better than being killed.
A penny dropped wouldnt hit the ground?? @riley1636
@@gonelucid Yes. The classic "penny off the Empire State Building will kill you" Pennies dropped off the Empire State Building just get blown onto the floors below. This is what I was referring to. It's besides the point though, even if they did hit you they'd still only cause minor injury. Same with tiny balls of glass from tempered glass shattering.
Windows keeps crashing, as usual.
Watch out for the blue shards of death
Yeah, easy solution is just to replace the Windows with some Mint.
Widows keep crashing? What happened to their former husbands?
thank you, jowjor
Except the mint only works 10% of the time and most of the time won't be compatible with what you're trying to do @@oxylepy2
I went to college in Boston in the mid 1970s. When I moved there, the John Hancock Tower in Copley Square had just been completed after terrific problems with its glass curtain wall. About half of the building's glass had popped out and fallen to the street during construction. For years most of the tower's facade was covered in plywood panels. People joked that it was "the tallest wooden building in the world." By the time I moved to Boston all the glass panels had been replaced, but the memories were still very fresh. While the original glass was a major part of the problem, it turned out that the building was oscillating in the wind far more than anticipated, which contributed to the problems with the glass. The building needed to be structurally reinforced, at great cost. Fortunately, it hadn't been occupied yet, but as a result the opening was delayed by about four years. It is a beautiful feat of architectural sculpture, due to its shape and reflective glass. From certain vantage points ot practically disappears or seems like a two-dimensional cutout on the skyline. From the structural point of view, it was a powerful and very expensive object lesson in engineering hubris.
wow, I guess so!
I wonder how many birds die as they hit the glass.
@brunodesrosiers266 Replacing the whole curtain wall system makes perfect sense to me. When I tried to find out exactly what had gone wrong I kept running into nondisclosure agreements made in response to lawsuits, but this was many decades ago and I don't know whether those agreements are still in effect. Despite the colossal failure, it didn't seem to affect IM Pei's (the architect's) practice too badly.
It was a mess. The city had to close the streets for blocks around when the wind blew.
After the the original windows were replaced, you could find used John Hancock windows in resale shops throughout New England. I saw some.
@@Liisa3139 The overwhelming percentage of birds that die in human settlements die due to outdoor house cats killing them.
Thank you for saying "inaccurately balance risk and cost" rather than pretending we don't have to balance risk and cost.
The New York sidewalk "sheds" aren't there semi-permanently either because they're needed for inspections (they aren't) or because they'd be expensive to remove. Instead each one represents an instance where a potentially dangerous façade has been identified by inspection and so the protective shed mandated but it's much less expensive to pay the fines imposed by Local Law 11 - not revised since it was introduced - annually for not doing the repair than it would be to repair the building. If the city would just update it's schedules of fines in line with inflation more repairs would be done and so more sheds taken away. Just another example of New Cork City's love of incompetent governance.
It makes so much sense now. Last time I visited NYC, like 50% of the sidewalks were covered by these scaffolds. I had no clue I was walking under a potential death trap that building owners don't feel like fixing.
Now I understand why people don't want to live in NYC anymore.
It's always cheaper to do the right thing. CNA could have replaced the windows first and saved $18 million and someone's mother.
.....in the long term. The problem is a short-term profit mindset, especially among geezer executives who won't be around to deal with the long-term consequences of going cheap.
Even the cheaper solution would've been fine in this case, as it gave them ample warning time, if they had bothered to immediately replace any cracked windows held in place by the film instead of letting them sit there for months until it failed.
True
Economic principles like present values tell us that profit motivated people will always choose money now over money in the future. Save money now by cutting costs means investing and growing that money for the firm to have more later so much more later that it's worth ignoring dangerous faulty designs because it's worth taking the risk that something could maybe happen later on and just paying the legal fees to deal with it. Something did happen? This is fine legal fees will be paid for with returns made off capital that was invested instead of being spent on repairs.
@@wheeliebeast7679its not they wont be around its that it is more profitable to invest that money instead of repairing things. Just take some of the returns on that investment to cover any legal liability that might happen in the future.
Wow for most of this video, I didn't think the building owner was _that_ negligent. But then when he said that the window that fell and killed someone _had_ the film on it and just was put off and pushed down the list of repairs really changed it for me. Can you imagine being one of their family members? The building is freaking red so it catches your eye. I bet every time they see it, it brings back some part of the pain from losing them. It's ironic too that it would be a red building. It's almost like they have been warning people to stay away since the beginning because red often means danger
The loss of windows at the Sears Tower came from failures in the outer skin of the glass. Slag from welding on higher floors scarred the glass below allowing it to fail.
As a Son of Contruction workers n welders that’s sad They know their work Is suppose to test time my father in law 70 years old when we ride around the city we see atonnof building he set 30-40 years ago standing strong
The Bernoulli effect may not be a commonly understood concept, but pretty much everyone in Chicago gets it on practically an instinctual level. Walking around a tall building between the high pressure and leeward sides allows you to experience the effect firsthand - watch as people brace themselves as they enter the low pressure zone and also pay attention to where the smokers gather (lol).
I'm surprised that even after all this time most Windy City towers are still incredibly blocky. You'd think given the stresses put on them more Marina City-style buildings would have risen... Alas...
Canada's tallest tower outside of Toronto, the 251m tall Stantec Tower, in Edmonton has been notorious for his shiny glass facade cracking and smashing into the ground below ever since it was opened back in 2018... For a while there was a pane a month falling from the tower it seemed. While it may not have been that bad it did kill all semblance of pedestrian traffic in the area and as a result a lot of the development in the surrounding ICE District has failed to flourish. Food hall? Still just a shell 6 years later. Cinema complex? Scrapped. Pharmacy? Shuttered after less than a year in business... I know I've only been to it twice or thrice since it opened and I basically sprinted through the plaza on the way to the arena. Maybe there's something to be said for more traditional facade materials besides wafers of melted sand...
I'm happy to know this. Edmonton just keeps on failing.
Car side windows are tempered, and windshields are laminated. It's interesting to see how that works out at a larger scale!
Be very careful, a lot of cars produced 2018 or 2020 and later now often have front side laminate windows. Look for information near the bottom right of the window, look at all 4 of your windows. This was due to federal requirements on ejection / limbs outside vehicle in rollovers.
So those escape / safety tools no longer work on laminate, they just cause a small crack.
@@AcridWhistle Good to know! I haven't kept up with new cars since leaving the automotive field a decade ago. I like my 80s and 90s cars too much.
@@AcridWhistlefire academy student here, thanks for letting me know, I'll keep it in mind for the future.
Yes thank you. This guy calls it tempered glass when it’s laminated glass. Makes me wonder how much else he got wrong if he can’t get the windshield glass correct.
@rjgaynor8 and the clip that followed even described laminated glass!
Great video Stewart, I'm going for a job interview tomorrow for a glass manufacturer and you bring up some great points of how the designs can fail.
report back, let us know how the interview goes! Did you use anything you learned from Stewart to impress them lol
@@CrazedComposure It went well, the facility has an automated line which does take out some of the human factors like delamination due to moisture.
The 32 story Anthony J. Celebrezze federal building in Cleveland, Ohio, built in 1967, had issues with glass falling out. Moisture was being trapped inside and minor repairs had been done throughout the decades as quick fixes. But due to growing issues with safety and energy costs, something major had to be done, without disturbing the daily activities of the tenants. So, the entire building was wrapped with a new curtain wall of windows outside the existing windows. This was completed in 2015 for about $120 million. It looks like a brand new building now, but if you look closely you can still see the original windows behind the new facade.
Safety is as good a reason as any for that kind of project. I live near a downtown building that was enclosed that way in the 1950s; from a distance, it looked like a giant trailer stuck between two masonry buildings. About 40 years ago, they peeled off the cladding system and revealed a handsome Victorian-era brick building I had never seen before. I've seen stories about other old buildings covered up the same way when their style went out of fashion, then uncovered as fashions changed again.
omg. When you're hear that the falling pane was one of the "repaired," windows, you can't help but feel your stomach drop. There have been a number of pieces of glass fall here (Calgary) but to my knowledge, no one has been killed. We are in an area with extreme winds similar to Chicago: it's not unusual to have 60mph straight line winds once or twice a year, and every year has many days with 50mph winds. As far as I know, that's at the surface; I'm not sure what it is in high rises. I believe many condo buildings have bylaws regarding securing things on their balconies. I'd be very curious what they've done with the fenestration here regarding heat treatments, because we also have a huge diurnal variation in temperature. Sunny days can rise from 32F to 70F air temperature, and I'm not sure what that would translate to for glass surface temps in the sun.
Stewart, this was one of your best. Informative and timely and your tone was appropriate throughout.
Thank you very much!!
Wow
2:36 that's why you don't take your marble for granite
booooo
that pun rocked! I cracked a smile
When I visit a skyscraper with floor to ceiling glass, I freak out imagining walking into them and the glass falling out.
And that's why the wind is so bad in Chicago because you've got all different shapes of buildings and that wind is coming off the lake like nobody's business
Aeon Tower's twin in Toronto (First Canadian Place - it's the same building, but with the windows oriented horizontally rather than vertically) had a similar problem - one of its Carrera marble slabs fell off the facade in 2007, with many more at risk to do the same. The marble was removed, and the facade replaced, in the early 2010s - primarily with white glass tiles. Cost was CDN$130 million (US$96 million).
My favorite channel! Please do a video on how to transform bankrupted and empty neighborhoods… In Detroit we have whole neighborhoods that are empty and poor with thousands of abandoned homes and empty lots. How can the people of the city rebuild it? Is gentrification inevitable? Are there examples of a local population taking advantage of that situation and improving their conditions? How would an architect approach the problem or even think about it?
These are questions more centered around City Planning than Stewart usually covers and specializes in, but I too would very much like to see this video.
There’s not going to be an easy answer. Maybe Canada can buy it 😅
@@TheOfficialOriginalChad I agree, particularly as I'm interested in examples of urban gardens that you see in Detroit
I'm from Detroit, living up north. It terrifies me to think that I could be stuck in a rundown, even dangerous community if I hadn't left when I did.
'New urbanist' planners have extensive experience with this, and have accumulated a lot of knowledge about making safe, interesting places that will endure and inspire. Mixed-use zoning and code reform are critical for the activation of lively, walkable streets, to foster individual entrepreneurial opportunities, and to enable long-term economic viability. Housing and employment options for residents of varying income, age and social strata are essential to maintain a thriving community, whether old or new. The availability of financing and insurance for such development must be secured, as well as the approval of government administrators, utility providers, fire protection districts and traffic engineers, among others. Certain levels of density, porosity and interconnection are necessary to ensure convenience and efficient mobility. Consideration must also be given to the need for outdoor public spaces and recreation, schools and civic institutions, restaurants, bars and coffee shops, retail areas and entertainment venues.
Good planning work involves reviving and integrating successful development patterns from the past with the functional needs, values and aspirations of local modern life. The Congress for New Urbanism (CNU) promotes and supports these principles, and they're having a significant influence on planning policy in North America and elsewhere.
Many architectural and planning firms now specialize in this field, and a wide range of beautiful and useful books have appeared in recent years. There are also numerous informative lectures on TH-cam, from CNU members and others. If you're interested, look for talks by Andres Duany, Jeff Speck, Victor Dover, Leon Krier, and Stefanos Polyzoides for a start, and for the work of firms such as DPZ, Dover Kohl and Placemakers.
@@CrankyHermit what a wealth of information
Fascinating video! Would it be possible for you to do a video on the challenges of converting old office buildings into housing? That seems to be gettin a lot of steam lately
Imagine just walking down the sidewalk and seeing a guy talking to a camera about windows crashing down from the very building you're walking by, killing pedestrians
Most instructive. In addition to giving me an insight into the principles and practice of glazing tall buildings, this vid taught me that cost:benefit analyses are fundamentally flawed.
Stewart, do you have any recommendations for any books related to some of the topics you cover? I have been really enjoying your videos and would like to learn more
Keeps happening in Manchester UK too. Even some blocks of apartments with just a dozen floors have been completely covered in enormous stretchy nets for over 2 years to stop anything falling on pedestrians. All the residents have these ugly nets across their windows.
Slight correction on the car comparison. Windshields are laminated you even showed a pic of it. Side & rear windows are tempered and will shatter into little pieces
Moderne cars are starting use laminated glass on the side windows. Tempered glass has been found to be a potential risk for side airbags while laminate mitigates that risk.
In Cincinnati earlier this year, bricks fell off the top of the 600ish foot 90 year old Carew Tower, and they had to close the streets below
I worked on the recladding the Aon Center in the 1980s (at the time it was the Amoco building). I was in my 20s and wasn't licensed yet. Definitely an educational experience.
4 months without a repair, while knowing the likely outcome is atrocious.
Sounds like your parents marriage
i have a constant if quite minor fear of this happening to me every time i walk around Chicago or any other city with tall buildings and this does not help me haha
I LOVE videos like this with more building science in them! The relationship between the art & engineering halves of architecture is not commonly talked about, at least that I've seen on TH-cam.
This whole self certification thing seems like a bad process whatever industry it's in. Cough Boeing.
"internal affairs"
They probably had dpmething to do woth setting that up lol
In an extreme case of shedding glass and building parts: I was in Houston in 1983 after hurricane Alicia. The streets were covered in broken glass shards and metal facade parts. There was glass embedded in wood and dirt. One literally could not have survived being anywhere between buildings. Roof gravel had blow off of badly maintained roofs and broken windows that might have otherwise survived. It was not like the total loss of structures like the tornadoes I've seen, but it's the next worst thing.
This may be a dumb question, but why don't they just install the windows from the inside instead, make the casings surround the exterior of the window more, and allow an interior gap to give the window some expansion room? That way, if they do fall, they'll fall inside. And I know, they could still kill someone or seriously injure them, but it just seems like it would be easier to deal with that way.
I was thinking about the glass falling out of buildings in SF recently, glad to hear that mentioned
Another outstanding video Stewart. Keep up the great work!
Hi Stewart, great video as usual.
I don’t like skyscrapers for a hundred reasons. Maybe unfounded reasons, then I see vids like this. And there’s plenty of building failure vids.
I was working in the CNA building that day. On the 5th floor at Mack and Parker an insurance company. It was very sad when this happened. The kid was just trying to wake the mom up until a bystander grabbed the kid.
Happy to live in stockholm where buildings have max 6 stories
I've worked in many high rises. In most of them, the windows were 20-40 years old and were still holding up well. Never encountered a broken window. Then we built one building about 12 years ago and have spontaneously lost about 30 windows to shattering over the years. Mostly ground floor windows but some at higher levels. We were quick to blame vandalism but have ruled that out. We never have come up with an adequate explanation, other than this is the first building constructed with Chinese made glass which may be of a lower quality.
2:55 This building used to be the headquarters for Bank of America. It was the tallest building in the city when it was built. I remember looking down at the street below and momentarily thinking that the window in front of me might pop out. Apparently, the thought had some validity.
This is like one of my worst nightmares that you lean on a stirdy skyscraper window but it actually breaks
How could architects, who should know about material science, choose marble over granite not knowing of the probable outcome? Was anyone called out over the decision?
I'm an engineer. These decisions are always aesthetic after financial. You change materials when the owner can't afford it. If you say it can't be done, they hire another firm. Longevity is a future problem that doesn't exist for construction management or the list of temporary owners.
Famous marble buildings include the Taj Mahal, Supreme Court, and Lincoln Memorial. It's a very common building material. The problem on this building may have been using it in thinner sheets, which then had problems. There is a challenge in materials science where manufacturers are always coming up with cheaper solutions, and sometimes it takes a few years before the problems with the new material or approach become known.
@@MTBSPD Don't they make panels of more flexible materials like cement-board, with thin marble veneer glued to it? I'd think that if they used the right cement, that would keep very much of the surface from chipping off at one time.
Because they are architects, not engineers. Their primary goals are how good it looks and how usable it is. Even tho they do need engineering skills, they are limited, compared to those of an actual engineer. And both tend to work together on projects. It's not that architects need more engineering knowledge. It's that people in charge need to consult with engineers and not gamble with risks.
I used to live in Chicago when that incident occurred. I never forgot about it.
1:48 the shadowed glass does not remain the same temperature, it warms through conduction, albeit very slowly. the expansion does not occur with a discontinuity, but a significant differential
I almost got hit by a sheet of ice after a snowstorm in Midtown NYC on 6th ave! Ish was scary as fudge!
Not even joking, I almost got hit by an 8 inch very floppy, just recently used dildo thrown out of a window of an apartment building in Manhattan. The reason why I knew it was just used a couple of minutes before is because as it landed on the pavement, it was completely glistening in female body fluids. I looked up and for a split second saw two people pop their smiling heads out of their balcony ledge and pop back in when they noticed me looking up.
I wasn't too amused, but I can imagine they were laughing hysterically, which is exactly how I would have reacted if I almost hit someone on the head with a glistening and dripping moist dildo from my apartment balcony.
I just kept walking cus that isn't even in my top 20 of the weirdest shit I've experienced in NYC.
Sheesh, a mom being struck by a huge slice of glass right next to her kid sounds like a scene straight from a slasher horror movie. I wonder how much of those 18 millions go straight to therapy over the years.
I love all the gorgeous shots of the Chicago skyline you include- our city has such beautiful architecture, and your videos are not only informative but visually very pleasing to watch :)
They will need to modify those little sidewalk signs from 'Caution Falling Ice' to 'Caution Falling Ice/Windows/Facade'. That should solve the problem.
Not the stuff of your typical "architectural tour" A bit technical but required viewing for anyone who lives and works in -or merely visits- a skyscraper district. A cautionary tale and literally a matter of life and death -and, for those to whom it matters, dollars. Worthwhile and well done.
Excellent video, Stewart. As always.
Really love this channel! Keep up the good work Stewart, cheers from Berlin.
“Buy once, cry once”.
When I lived in NYC several people were struck and/or killed by falling icicles or sheets of ice from skyscrapers.
1) Incorporate building as its own entity
2) Use cheap materials
3) Be long gone before you kill someone
Mini physics lesson with Stewart!
10:55 They shouldn't be prototypes, except for in the vaguest sense. These are buildings, not toys. They can and do kill many people. I think you should treat the fact the fact that these buildings killed people much more seriously than you did in this video. It could have been you.
Awesome video, earned my subscription!
I was interested just from the thumbnail, little did I know it was about an incident I didn't know about in front of a building I used to pass daily!
Love the style and insights. Thank you
1:28 I think you mean “infra red” rather than “UV”. Heat radiation is infra red.
Thanks Steward, a very important video. Simple and highly informative! The problem is going to become increasingly important due to to Klima change. Very few of our Ingenieurs are looking in to the consequences of the difference between our models and the reality we are already experiencing. The problem is particularly pronounced with listed modernist buildings here in Scandinavia where there are strict requirements to preserve geometry and, not least, relief. As you say, it is extremely important to be aware of the solar influence on the glas by even a modest relief effect and the resulting tensions. The pressure differences are an equally important factor, I am there where technically you might have to handle the facades more individually than we do now. Jesper from Copenhagen
1:00 so it is as more like a design award than anything to do with sound practices?
It's easy to look at what the right decision is in hindsight, but at the time, they were probably trying to figure out where they could pull 300k from, let alone consider 3 million.
Now if only they would stop making skyscrapers that are just giant rectangles clad in a glass facades, modern skyscrapers seem to just be worse in every way with these designs, they are bland and ugly, glass facades frequently falling off, and they are harder to actually heat and cool vs old buildings.
Are they really less efficient versus old buildings? Seems like that's not necessarily true due to the way modern energy standards have been applied for at least the past decade, if not longer. Cite references please.
The only problem with that is most of the time is spent in the building, where it's a lot nicer to look out floor to ceiling windows that let in much more natural light which boosts mood and energy. Smaller windowed buildings with classic designs can be much more appealing from the outside but much less enjoyable on the inside.
Stay in a room with floor to ceiling windows for a night and try to tell me that it isn’t an extremely desirable design feature. Also, I doubt that’s even the primary issue, the problem with Aon Center wasn’t even the glass at all, plus Aon and CNA are both over 50 years old, with much less glass on their facades than most modern skyscrapers.
I dont mind a lot of glass, but if there is too much, like covering the entire thing, i dont like it. Add like a strip of decorative metal or something.
Agreed. These hulking glass towers are butt ugly and good at nothing. And they’re unpleasant because the floor to ceiling glass makes it feel like you’re going to fall through the window.
By far the best and one of the cheapest way to strengthen glass is by using a potassium salts treatment to reoganize the glass molucule structure.
Makes glass over 15x stronger than regular tempered glass. It was invented during the 50s in east germany because of a glass shortage.
After that glass shortage it has never really been used again up until recently: it's often used for things like smartphones where it's called "gorilla glass".
Because production of that chemically treated glass has been basically 0 for half a century, production facilities for larger pieces still don't exist yet...
In towers tall, where dreams ascend,
Glass windows gleam, a skyward trend.
Yet amid the heights, a flaw unfurls,
A strange affliction, a plight of worlds.
The Weird Flaw Plaguing Skyscraper Windows,
A tale of caution, where danger grows.
From Chicago's CNA, the story's told,
Of windows falling, a fear unfold.
In design's embrace, they're set with care,
But sometimes fate's whims, they cannot bear.
Physics at play, a delicate dance,
Where forces unseen, may wreak their chance.
From towering heights, they meet the ground,
With a shatter loud, a mournful sound.
Why does this happen? Many inquire,
As shards cascade, like tears of fire.
In this video's realm, we delve deep,
Exploring secrets, the reasons to keep.
From stress to strain, and winds that blow,
To flaws unseen, that silently grow.
Prevention's key, a vigilant eye,
To spot the signs before they fly.
Structural checks, and laws in place,
To safeguard lives in urban grace.
So heed the lesson, this cautionary tale,
As skyscrapers rise, and winds assail.
For in the heart of each towering sight,
Lies the weird flaw, lurking in the light.
beautifully written, and terrifying...
a stop sign made of lace
Frackiing also contributes because'it brings on earthquakes and well water polution. How o how can you wash windows'with poluted water.
I used to work as a designer for an architect's office and when the engineers tell you which buildings to avoid, you listen.
A great video as usual. I know it isn't connected with your content but I have to say you're one of the few men who can pull up a moustache.
0:18 the building's original owner * 😊 namaste
Or the original building owner 😊
The Chicago skyscraper architects should look into making the footprint of their skyscrapers that of *a parallelogram.* No matter which direction the wind blows from, you never get a “leeward” suction side.
Should be running Linux on our skyscrapers. 😀
The semi-permanent scaffolding thing is a weird predicament. On one hand, it's ugly all year round, but otherwise, you're actually protected from rain and falling debris.
While living in Vancouver, where it's constantly raining, I always wished there were more overhead on the sidewalks.
I got hit by a chunk of ice falling off my office building in the Loop a few years ago. It hit my foot … and it shocked me so much I almost pooped :-/
First time I heard about the problem was from the pyramids on the north side of Indianapolis. The sloped side was all glass. As the temperature dropped. the panes shrank. Then, the glass would fall inside the building. It was a cost cutting measure that backfired after they had to replace all the glass on the south side of all 3 buildings.
Before I even hit the play button I was thinking CNA. Every time I walk by it I can’t help but think of all variables of that woman’s day that put her in that spot at that time.
The windows at 200 Clarendon St (formerly the John Hancock building) fell out when it was windy. Thermal stresses were part of the problem.
In New York City I always feared those Gargoyles high on top of our buildings! People were killed by Gargoyles, stones etc. Don’t cities inspect these things regularly??? 😅 Heads-up! In-coming Gargoyle! 👹
The Gargoyles are even more dangerous at night! Especially when they fly around the city.
Stewart, love your channel, super enjoy your love of architecture as I lived in "Chi town" for over nine years. The first fives years were with a CPA firm that seemed to include an invisible clause in my contract that I had to work only in 90+ story buildings! Summer: Sears Tower (don't care, I'll never call it by another name, no disrespect to "Willis") Winter: John Hancock Tower. Sadly, my roommate, another CPA worked in the CNA building and during the time of the accident you reference. So very sad...
Even though I left being a CPA though a numbers person I love architecture and that which is in Chicago. However, given falling sheets of ice in the winter, breaking windows, falling sheets of marble (from the Amoco building, as I knew it back then). While this URL relates to a totally different subject, I believe it is applicable here given the starting point I want to include (5:01). th-cam.com/video/DutJLb-c0vs/w-d-xo.htmlsi=nagYrDyFMa7NKPb0&t=301. I appreciate the inspiration, but wake up!
Stewart, I tend to visit Chicago in May & November. Careful, I might just reach out and hug ya! So appreciate the work! Just sayin'
Architects should be held liable for flawed building features. Maybe that way they will be more focus on sound building practices than winning self-serving awards. There is no excuse for windows falling out.
If I remember my history right, the Babylonian Codes of Hammurabi, one of the oldest written laws had death as punishment for builders whose structures caused death. And if their construction failed without any death they had to rebuild it with their own money.
For an accident 50 years later at the cna building?
That's a fast track to a world with no architects
Architects have little to no say in the final construction practices taken. The general contractor or engineer who signed off on the plan would ultimately be 1) considered fully or majorly to blame and 2) held fully or majorly responsible.
Why would an architect be responsible for a construction companies mistake? Are you dense? Lol.
Every major city knows which buildings are the problem. I visit major cities in the USA and Canada and I am smart enough to know what side of the sidewalk to avoid. Typically each city has only 2 or 3 buildings that are a problem. Don't park your car or walk on the sidewalk under them!
Another vote for @Dysprosio2's request for including metric. Actually, you often do -- even in this video, for example, when at 7:35 you say ‘6 mm or ¼" thick pieces of glass…’
Building it into the script is kindest I suppose, but can get tiresome with lots of numbers, in which case just subtitles or perhaps flashing the metric equivalent on screen can help keep it simple for all. And it's often not a big problem - many people can picture common measurements such as the ¼" mentioned, for example, but might find pound-force per square inch as esoteric as pascals, and I easily understand that 165 lbs of force on windward windows is quite a lot smaller than the 1,000 lbs of suction force on the other side without the metric equivalents of 75 kg and 454 kg. But including metric really does help, rather like knowing a few phrases in a foreign language when on vacation.
Crazy. My mom worked for CNA for years out of Portland. She ended up leaving after my grandfather died to a company that treated her much better (even allowed her 2 weeks paid vacation right when she started, to handle gramp’s funeral arrangements and such).
@5:00 Same type of effect as an F1 car pulling out a manhole cover in Vegas. Physics can be dangerous.
The options should have been film the glass asap while replacing the most problematic windows with the new glass, ie the ones that break the most in the history of the building and the ones above the most walked pavement, until you can change all of them over time! Still not a defence for the tragedy that happened, but then it's an accident, not negligence.
“[This glass is really good at not falling out of the building and killing people, but it makes the sky look wavy when you look out through it, so we won’t use it]”.
Why don't we reduce the total number of windows, like modern skyscrapers is ridiculous with he amount of glass that basically totally cover the whole building. That would be less windows to worry about and less of a expense in the long run.
Can you PLEASE go metric at least on the captions? :(
International viewers will thank you.
Start using tempered glass. It’s. More expensive but when it brakes it shatters to pieces smaller than a size of a pea
We are living in the Tower of Babel.
I love how that story shows how terrible god is.
I love mythology
What, are people gonna start speaking french 2?
What're you babeling about?
I lived in Sao Paulo for a while. In front of the building where I lived, they made a huge office tower with a glass facade. Once, during a wind storm, the glass panes started flying away. It was a wizard of Oz view.
It is a totally different problem with similar results and most likely a similar source.
Buildings should be designed with aerodynamics in mind. Square buildings with sharp corners create all sorts of issues from increased urban heating and wind tunnel effects.
Tell me about it. It's shocking to see how those concepts are still seen as an afterthought to be dealt with...
@@stickynorththey're not...
They are...
I appreciate the effort needed to investigate this architectural problem. Very interesting. Would like to see more like this.
There is something you can do about it: don't build skyscrapers.
I mean... fair... 😅
Skyscrapers aren't the only problem though, any tall building would have the same problem.
This is so well presented and put together. Thank you.