If it's true that they didn't make any arrangements with police or the city, then I hope they're going to get billed for the policing, any damage, and the cleanup.
Depends on the person and the crowd! And their state of mind. A panicked crowd is ad irrational as a panicked individual, except their actions are amplified by their numbers. There are a few who act on their own and the masses who follow along because they think the crowd knows best.
I have been in traffic jams, get curious and take a random residential road trying to find a way out, and like 5-6+ cars follow me, even try to loose them and they follow me to a dead end street lol.