Shelter in place scenario

With campus carry legal now, and finally getting my LTC in, it got me thinking. Schools (even my college) occasionally do lockdown drills where we are all sent texts/emails to shelter in place. This would be the procedure for a violent situation on campus.At what point does my ccw come into play, in your opinions? We are behind an autolocking door that needs a key card to open. Most classes have ~30 people in a room, plus anyone in the hall looking for a place to hide.Obviously I am not going to charge around the building looking for the baddie. Im just curious when you all think letting those around me be aware of the presence of my ccw. Right now I am leaning towards the idea of waiting until it becomes obvious the baddie is outside our actual room, but by then maybe they have already busted their way in somehow.Thoughts? via /r/CCW http://ift.tt/2xPg1iE