They don't know because Boulder is a far left town. Even by Colorado standards. They don't want to say what they know it is. They'll do everything they can to call or everything but what it is. A terror attack.
Alot of people think as soon as they start resisting arrest, all they have to do is yell "I can't breathe" and the cops should let go. If you keep saying I can't breathe, you're breathing.
I live in a smaller town in Wyoming. The school districts communicate weather related closures. The weather service sends alerts regarding sends events. Not once has NPR sent anything to anyone here.