@ Veeger, I disagree. If the pumps at the water treatment facility stopped for some reason, water pressure drops as soon as the towers empty (they're gravity accumulators), at which point, "it's boil order" upon pump restoration.

No water, no "flush the poopie". No fire protection via hydrant. I could extrapolate a thousand such things, that were they to happen, the city would be gridlocked. Recall, it was one pissed off employee damaging a radar / traffic controller hub - that disrupted O'Hare traffic control. I think he lit a fire in a garbage can. Maybe he had wire cutters. 1 guy.