system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If no workers were operating on their systems, how long would it take for water and electricity to shut off for residential homes?

As in, if people suddenly disappeared, would the water and electricity run indefinitely? Or would they eventually shut off from others?
gpt
In an apocalypse scenario...

Power would go off pretty damn quick. Nuclear plants that have safety locks would shut down within 12 hours after people stopped checking on them, and safety lockouts would automatically disengage the rods preventing any nuclear fallout. Coal plants would run until the fires died, without people to feed the fires, they would be done within hours. Oil plants would last the longest, burning oil until they broke down or ran out of fuel.

Solar or Hydro plants could essentially continue running indefinently until they broke down.

Water would stop flowing when the power died in urban areas with city water. Well water could keep going until pressure was down and water towers would continue to gravity feed water until depleted.

Sewers would back up almost instantly once water sanitation stopped.