Sacred Haven of Debauchery

Wouldn't it have been possible to hold your breath for about half an hour and save a couple of classmates?

Well, if you're already in smoke, you shouldn't underestimate the danger and talk/breathe calmly; you should inhale as carefully as possible, preferably through fabric (like clothing). Maybe it will help someone.
By the way, there were no casualties, and the only one who could have been harmed was me, and that only because of my own stupidity. Only one room burned down, although there was a moment when the entire wing was filled with smoke (I and one other guy led the firefighters there, and then we and the remaining representatives of the university administration were kicked out of there).