What gives you the right?

The massacre at the printing company yesterday has been haunting me.  I am a teacher and we have to perform lockdown drills in the event that a bad guy will come in and go all Columbine on us.  Maybe all organizations should perform these exercises.  I prefer to be prepared and never need to use it than to be surprised and have no idea of what to do.  I wonder what my husband would do if someone attacked his office?  One more thing to worry about.