I was at a Mariners Game, when Arod used to play, and he got hit in the head and was on the ground for like 15 minutes...That was scary.
When Johnny Damon got ran into by Damien Jackson, that was scary too. I was wishing I was an ATC right then.
Not MLB, but our HS catcher got hit in the head with the bat and had a light concussion. And I WAS the ATC then, that was scary.