We had an area of the house on a particular circuit breaker switch. All those outlets on the switch went out at once, but the circuit breaker wasn’t tripped. There were no GFI outlets in that area either. With these annoying tamper resistant outlets that builders are having to use to meet code, you have to jiggle and shake plugs to get them plugged in. In this case, it probably loosened the wiring behind the outlet, which disconnected the other outlets, the electrician said. Seems like the tamper resistant requirement was made without the hardware being ready for primetime.