Sounds like intentional infliction of emotional distress to me. Best the taxpayers go ahead and get their checkbooks out now...
Everyone who was part of that or approved this exercise should be immediately and very publicly be fired. I'm surprised the Teacher's Union isn't freaking (assuming it isn't).
As a poster noted above, if you're going to play this game. Have a day with real training and scenarios then. There's a reason firedrills are announced before hand.
And what happens if there was a spouse who was a cop there or happened to be going by and heard screaming? How many of these actors would end up bleeding to death?