What do you think are the best ways to warn students at large universities of emergency situations?

Question

(or other institutions like high schools, etc)

Answer 1

At this point I think most people have cell phones. Maybe the school could set up an electronic address list and in case of emergency, a text message or voice recording could be sent immediately to everyone's cell phone as well as their e-mail address. And perhaps there could be a high-pitched warning signal that could be sounded over an outdoor sound system which would only go off when there is some sort of imminent danger and students are to stay in their locked dormrooms or what have you. That way, even students who were driving to campus would have heard it and known to just turn right back around and go home until further notification.