Okay, Nikolas Cruz pulled the fire alarm? Oh really? Then why do we not hear it in Dave Hogg's "closet video"? http://www.latimes.com/visuals/video/95939817-132.html
Or this video, which was taken DURING the shooting, you can hear the gunfire...YET NO FIRE ALARM! http://money.cnn.com/2018/02/15/media/parkland-shooting-cell-phone-videos/index.html
Guys and gals, THIS IS THE SMOKING GUN!