The Northeast Blackout 2003

The Northeast blackout of 2003 was a widespread power outage throughout parts of the Northeastern and Midwestern United States, and most parts of the Canadian province of Ontario on Thursday, August 14, 2003, beginning just after 4:10 p.m. EDT.[1]

Manhatten regained power by 5 a.m. August 15

Reference: https://en.wikipedia.org/wiki/Northeast_blackout_of_2003