Have witnessed or heard about a few unusual, disturbing, and a couple that are just amusing:
This happened during a boys varsity game this year. During a time out one of the home school cheerleaders begins a tumbling pass across the floor not realizing that a visiting school cheerleader is doing the same thing from the opposite direction. They collide at midcourt. The home team cheerleader lands on her head and doesn't get up. She underwent brain surgery the next day. I wasn't there, but have friends that were, including one official on the game. He said it was a little like watching a train wreck, you could see it coming but couldn't do anything to prevent it.
Girls JV game a couple years ago. One of the juniors that also starts varsity, one of their "bigs", is warming up while waiting in the layup line by repeatedly swinging her leg in a broad arc forward and backward, swinging higher each time. She swings it too far forward, pulling herself upward off the ground and flipping her over backwards. She lands on her back and smacks her head on the floor. She's done for the night.
Rural school game, cheerleaders on the sideline opposite the table. No bleachers on that side of the gym, plenty of room for them. But, of course they creep closer and closer to the court. During one transition I wave them back. During the next transition my partner is looking back over his shoulder and clips one of them, sending her spinning across the floor. As she goes skidding across the floor one of the other girls is heard to say, "He told you to move back!" Fortunately she was okay.
Girls JV this year. Held ball, very strongly contested. At the whistle one girl lets go just as the other one makes a very energetic attempt to pull it away from her. The sound of a human skull hitting hardwood is never a pretty one. One of her players begins trying to pull her up, not good. She's on the floor a few more minutes before the trainer helps her up and escorts her out. She doesn't return.
It's been a rough year in the Mountain West Conference for Dave Hall. In one game earlier in the year the crew had to continue without him for a while after, if I recall correctly, and errant pass connected with him. I heard conflicting reports about what happened, but one authoritative sounding report a few days later indicated he'd be caught in the ... ummmm, midsection? Then just a couple weeks ago, at BYU I believe, a camera man collided with Dave during a time out, hitting him in the head with the camera. It was a while before he was ready to continue.