Something like this happened last year at Six Flags: Kentucky Kingdom. This girl was riding the "Superman Tower of Power" ride, and a cable snapped and sliced off both of her feet! It happened only months after I was at the same park, and my sister and cousins rode the ride like, 5 times! CREEPY.
I feel sorry for the kid's family and friends, but quite honestly, the kid should've known better. Jumping two 6-foot fences (which undoubtebly had warning signs) just to retrieve your hat? He could've waited until the ride stopped, or asked an employee or something...