This just does not happen in our schools. This past week in Boston a "Stay in Place" was ordered to Boston and surrounding towns while there was a manhunt for the suspect in the Boston Marathon Bombings. Residents were instructed to stay in their homes while law enforcement went door to door clearing neighborhoods searching for the suspect. I bet this is the first time many people had heard the term "Stay in Place". Even after an area was cleared, residents were even instructed to stay in side for their safety. Many times staying inside and not evacuating is safer, it depends on the situation. Again listening to law enforcement is critical.
I can not emphasize how important it is to follow instructions. They are for our safety.