The US has three “independent” grids so losing them all would be hard. But I believe at times Texas has gotten close, and East went pretty dark at some point recently.
CA of course has rolling blackouts for other reasons.
2021 would have been a non-event if people in Texas weren't propagandized about some nonsensical "Independence" bullshit.
A few more interconnects with the rest of the country and it wouldn't have even made the news.
this is after decades of Texans bragging about their independent power supply. Many Texans still believe outright lies about the blackout, like it being "caused" by green energy sources, which was false.
It was caused by free market participants not spending capital to harden their network. Solar panels and Wind Turbines work great in the cold climate of Canada.
The storm that caused such a problem is a once every ten years storm. The grid companies all should have foreseen this with even minimal investment in planning. They didn't, because that's less profitable, and the "regulator" in Texas has no ability to punish them for pinching pennies on reliability and resilience.
CA of course has rolling blackouts for other reasons.