There are three main causes of parachuting accidents. Parachute equipment failure being the most common, followed by mid-air collisions between jumpers and difficulty in landing. The equipment that usually malfunctions is the canopy or reserve canopy. This is ironic because a skydiver has 2 canopies, the main and reserve and it is quite difficult to fathom how the two of them will malfunction at the same time.

I think the main culprit is actually operator handling of the equipment. The lines of the canopy usually get tangled rather than the canopy failing or breaking. So it isn’t really a parachute equipment failure but rather a failure of the jumper to pack the canopies properly before a jump.