Massive hurricanes striking Miami or Houston. Earthquakes leveling Los Angeles or Seattle. Deadly epidemics. Meet the “maximums of maximums” that keep emergency planners up at night.
I don't think many people realize (or maybe they just ignore) how fragile our civilizations are. Katrina was a prime example of how easily the system can break down and that was just one city. Can you imagine a regional (or nationwide) loss of infrastructure?
I'd guess that within 48 hours of losing electricity people would begin to panic, and within the week without food and water there would be rioting. Just the internet going dark would cause mass confusion. We've connected every facet of our lives to it. I have little faith that our government would be able to support everyone. It would be martial law.
Sorry I sound like a nut. This shit interests me. We have overextended ourselves as a species and nothing lasts forever. One major clusterfuck and it will all tumble down.