Don't know, but I did once watch a teammate break his neck on a routine high jump onto pads/cushions. One good whack in the wrong angle can do a lot of damage. Scary.
I saw a Serbian player in the Greek professional basketball league break his neck and paralyze himself by hitting his head against the basket support stanchion. He was upset with himself for making a bad play and walked over to the padded basket support and hit his head against it. It was a freak angle and he was paralyzed from the neck down. Tragic case that demonstrated how easy it is to hurt yourself very badly without trying to.