One critical event that could really hyper-escalate the chaos and carnage: regional loss of power, by the downing of a utility pole or something flung into the many exposed substations.
That's for sure. But at 5,600 words, I had to stop the scenario escalations somewhere. I sort of covered that with the infrastructure channels being at risk, but you are right. And sometimes, gangs put the lights out on purpose, by cutting lines to adjoining areas, to make them easier to rob and loot. That can begin a deadly cascade of events all on its own.