The explosion is found out about at the school at 11:30. The principal calls an assembly and announces it. Hydrogen Cyanide was being used at the steel mill, and a tank of the stuff exploded after overheating. It's believed that the gas is around town, and it's exceptionally poisonous to inhale. The school goes on lockdown to avoid anyone going into the exposed town before the chemicals dissapate.
Emergency assembly, fifteen minutes.
"Okay, folks. First day, not going to be a great one. The steel mill blew up, for some reason I'm not really sure of, and the air outside is toxic because of chemicals and blah blah blah, do I look like the science teacher? So, everyone, we're all stuck here. Close all windows, remain inside, stay here for lunch, and try not to go crazy. We'll probably be staying here after school, so go ahead. Anyway. It's your first day, I'm your principal, yeah, I used to be a woman, yeah, I'm bi, I fucking swear sometimes, go complain, but I've gotten complaints and I'm still here, so…welcome to William Mason High, and please don't leave until the police tell you it's safe."
Shortly after this address, the principal committed apparent suicide, leaving an open window.