I just happened to find myself in the middle of a school lock down drill at an area middle school last week. I was working with a teacher on creating an EduBlog when the code came through on the intercom. So. . ..the usual locking-of-the-door took place and we huddled in a corner where we could not be seen. All of that is ho-hum, but what fascinated me was that the teacher immediately sent a quick email via their FirstClass school conference regarding the status of her room. Cascading clinks could be heard as classroom teachers and others reported out. I'm guessing within five minutes time, everyone at the school knew what everyone else was doing. Neat.
WikiHow "How to Behave in a School Lock Down"