DJI Phantom 2 crash

We learn from our mistakes. First high altitude flight of the phantom 2.
The first mistake was I took off before GPS getting a Home lock. Phantom 2 was flying smoothly, and I didint pay attention to the battery level. It then went on to Auto Land mode and started descending from where the 6th GPS satellite latched on, and where it latched on was a construction site it did land safely but there was a steel bar on the floor which hit the phantom and the phantom tilted. The motors were spinning till the time i could reach the crash site the motors heated the body panel and came out. Total Damage, One motor needed to be replaced and entire body shell.