By: HISTORY.com Editors

1965

The Great Northeast Blackout

Published: March 04, 2010Last Updated: May 27, 2025

At dusk on November 9, 1965, one of the biggest power failures in history occurs as all of New York state, portions of seven nearby states, and parts of eastern Canada are plunged into darkness. The Great Northeast Blackout began at the height of rush hour, delaying millions of commuters, trapping 800,000 people in New York’s subways, and stranding thousands more in office buildings, elevators, and trains. Ten thousand National Guardsmen and 5,000 off-duty policemen were called into service.

The blackout was caused by the tripping of a 230-kilovolt transmission line near Ontario, Canada, at 5:16 p.m., which caused several other heavily loaded lines also to fail. This precipitated a surge of power that overwhelmed the transmission lines in western New York, causing a “cascading” tripping of additional lines, resulting in the eventual breakup of the entire Northeastern transmission network. All together, 30 million people in eight U.S. states and the Canadian provinces of Ontario and Quebec were affected by the blackout. During the night, power was gradually restored to the blacked-out areas, and by morning power had been restored throughout the Northeast.

On August 14, 2003 another major blackout occurred which affected most of Eastern Canada as well as most of the Eastern United States.

Photos of the 2003 Blackout: When the Northeast Went Dark

For two days New Yorkers slept on sidewalks, walked home, even showered on the streets and generally made do as the city was crippled without power.

For two days New Yorkers slept on sidewalks, walked home, even showered on the streets and generally made do as the city was crippled without power.

By: Madison Horne

Timeline

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Citation Information

Article Title
The Great Northeast Blackout
Website Name
History
Date Accessed
November 24, 2025
Publisher
A&E Television Networks
Last Updated
May 27, 2025
Original Published Date
March 04, 2010