This happened a few years ago but it's making the rounds now. A skydiver posted video from the time he was accidentally kicked in the head and knocked out cold by a fellow jumper. And then a different jumper saved his life.
Four guys jump out of a plane together, and one of them is wearing a helmet cam. They're about 10,000 feet up and free falling at 200 miles-an-hour when two of them cross paths and the accident happens. The helmet cam guy sees the whole thing, and notices that the guy's body went limp, so he tracks him down and opens his chute for him. This part is even crazier. Even though the guy who got kicked in the head was knocked out, he found the drop zone and landed safely. He said later, "How I found the drop zone is beyond me." He added that he lost three days of memory.