In middle school, two kids in my gym class started jumping off the back of the bleachers and sliding down. At the top of these bleachers were rails to prevent you from going off the back side as they were doing, and at the end of the rails, a v shape. On about the 4th time they jumped off, "Shorty", one of the kids, was at the end of the rail, and he was holding it getting ready to slide down the flat wall on the back side. He lands on the ground and everyone gasps when he looks up and starts talking because he's bleeding from his hand. Turns out, Shorty had ripped his pinky off in the v shaped rail on the bleachers, and because of shock, he didn't immediately notice. He notices, starts screaming, gets rushed to the nurse, and I'm standing there next to a still twitching pinky trapped in a rail. The substitute teacher came and grabbed it with a piece of paper and took it to the nurse. Unfortunately, they tried and failed to reattach it at the hospital.
