Too heavy, the DHC-6 Twin Otter lacks of performance after takeoff and crashes

What happens in this video ?

This is a good lesson learnt showing how important it is to perform the takeoff performance calculation. This DHC-6-100 Twin Otter crashed on takeoff from the gravel airstrip at Muncho Lake, BC, Canada, on July 8th 2007. A post-impact fire erupted and the airplane was destroyed. 5 persons were onboard. One passenger was killed. Two pilots and two passengers survived the accident.
The take-off was attempted at an aircraft weight that did not meet the performance capabilities of the aircraft to clear an obstacle and, as a result, the aircraft struck a telephone pole and a telephone cable during the initial climb. And as the performance calculations were not done prior takeoff, the flight crew was unaware of the distance required to clear the telephone cable.