A similar thing happens here when a heat wave hits. Everybody is operating their window ACs and HVAC systems all at once, trying to keep cool. I can't find any evidence of it, but when I was visiting relatives in Bristol, CT when apparently my uncle in law was listening to police radio and heard that they were blocking off streets due to electrified ground? Apparently a load of houses had all their wiring shot.
I have no clue if this is true, or what happened. I didn't see it, and I just heard about it. Maybe someone with more than casual experience in the US power grid can give some idea as to what happened.