Next tonight amazing video of a mid-aires cue. A sky diver in freefall knocked out cold not able to open his chute. ABC's Dan Harris shows us what happened next. Reporter: This video starts with a... See More
Next tonight amazing video of a mid-aires cue. A sky diver in freefall knocked out cold not able to open his chute. ABC's Dan Harris shows us what happened next. Reporter: This video starts with a group of skydivers climbing onto the outside of a plane preparing to jump. The small camera is attached to the helmet of an experienced 25-year-old skydiver named James lee. He's done this more than a thousand times, but never before has this happened to him. Seconds after he leaps, a freak accident. One of his fellow diver's legs hits lee in the back of the head knocking him out. The camera goes wobbly as lee tumbles, unconscious, from 12,500 feet toward certain death. Slowing the video down, you can see his arms go limp. Skydivers fall at the rate of 120 miles an hour on average. Look what happens next, his friends notice something is wrong with him. They approach giving lee hand signals to check in he's okay. Seeing he's not, they reorient his body to the correct position and then deploy his chute. You can hear the hiss of the air relent as lee's descent slows down. It's pretty incredible when somebody is unconscious and tumbling, it's virtually impossible to catch them. Reporter: This is not the first skydiving mishap to make the news of late. Just this week, a 16-year-old girl in Oklahoma making a hard landing after her chute fails. In 2005 a pregnant woman crashing down after her chute malfunctioned. Both survived. As James lee drifts towards the Earth in the English countryside, he regains consciousness with no memory of the incident. When he lands, you can hear him exhale. Tonight he is vowing that this incident will not stop him from diving again. Dan Harris, ABC news, New York.
This transcript has been automatically generated and may not be 100% accurate.