On this day in 2003, a major outage knocked out power across the Northeast U.S. and parts of Canada. Beginning at 4:10 p.m. ET, 21 power plants shut down in just three minutes, and 50 million people were left without electricity. Many in NYC spent the night sleeping outside, unable to return home. Airlines canceled 400 flights.

Nightly Business Report
Five years after the worst blackout in North American history, the country’s largest power providers say the problems that turned out the lights on 50 million people have largely been resolved, but they fear that larger, systemic issues could soon lead to even bigger and more damaging outages, according to a follow-up report yesterday, August 13, 2008.

See the timeline of events leading up to the 2003 blackout.

NewsHour
Watch segments:
“Unplugged,” August 15, 2003.
“Power Failure,” August 25, 2003.
“Why the lights went out,” September 4, 2003.