Classroom Shooting: Hunter-safety instructor blows hole in library ceiling

You have to wonder how things like this happen: "Remember students: Never, ever load 28-gauge shells into a 20-gauge shotgun, like this. And if you do, make absolutely certain that you're not standing inside a public library, like we are now. And for goodness sakes, don't pull the trigger, like this . . . ."
http://www.billingsgazette.net/articles/2006/04/22/news/state/75-gun.txt