There was a teenage girl killed at a Columbus Blue Jackets game one year. They thought she was ok but I think it turned out to be a slow bleed in the brain or something? The CBJ had to start a scholarship in her name (at 2 high schools), my daughter was the first recipient at her school.
That's why the NHL now requires the higher nets to try to stop pucks from going out. DD dated a hockey player in high school, and actually her H is too, and we went to a lot of his games. I don't think I saw any pucks fly out at them.
The odd thing about DD getting that scholarship, a few years later our paper did an article on the girl, all the things she did and liked, habits she had. She was younger than my daughter but it was like a mirror. The sports they did, what they liked to eat, how they ate a couple specific things, etc.