Physical infrastructure can be fragile/fail catastrophically, as well. I recall starting a job near Seattle, 40 miles from my home in Olympia, WA and a passenger train derailed onto the highway killing a few people and backing up traffic for days. That was not a pleasant first day!
Damn this made me read a lot about this specific derailment, but also about Puget Sound, Salish Sea, Positive train control and all this 220-MHz stuff.
No but the failure caused a halt to all motor traffic on I5 in both directions which is possibly even more catastrophic than stopping the entire train system.
https://en.wikipedia.org/wiki/2017_Washington_train_derailme...