Statistics show that those who [i]react[/i] one way or another (fight or flight) are the ones who survive. A while back my department had a seminar with one of the survivors of the Virginia tech massacre. She explained how 12 out of the 17 people in her class were killed and how she was shot three times, but never froze up and never laid down to die. Almost always the best response is an immediate, aggravated, offensive counter-attack. If a shooter walks into a classroom with a gun and is instantly swarmed by 30 people, the situation won't be nearly as severe.