The worst that happens at real games is a puck flies and hits a girl in the back of the head and kills her.
"The puck struck her in the forehead, causing a skull fracture and some bruising of the brain in the area," Lewis said. "But that wasn't what led to her death. It was the snapping back of the head and the damage to that artery."
And now you see stuff like this at hockey games: Link
If you're not paying attention to the game, why did you buy a ticket?