The only plant I know of that has had a suspected outbreak sent everybody home from the shift with the infected worker and spread out the night shift guys to cover.

Most plants are run by large companies that own many plants, and can transfer in guys from other facilities.

Given how bad the initial outbreak was and only one of the dozens of clients of mine had a problem (that didn't cause a shutdown) I think things would have to get a lot worse than the first wave before you would see interruptions in power or water service.

I'm more worried about the lack of maintenance before the peak demand season in the summer.