Video: 'Blackout of 2003' (10 clips)

(Thursday, August 14, 2003, 4:10:39 p.m. EDT; during the Northeast blackout of 2003) — The Northeast blackout of 2003, a widespread power outage throughout parts of the Northeastern and Midwestern United States that impacted 45 million people in eight Northeastern and Midwestern U.S. states and 10 million people in Ontario, Canada, began today.

The blackout’s proximate cause was a software bug in the alarm system at the control room of FirstEnergy, an Akron, Ohio–based company, which rendered operators unaware of the need to redistribute load after overloaded transmission lines drooped into foliage.

What should have been a manageable local blackout cascaded into the collapse of much of the Northeast regional electricity distribution system.

Video: 'Blackout: The Power Outage That Left 50 Million W/o Electricity | Retro Report | The New York Times'

Most places restored power by midnight (within 7 hours), some as early as 6 p.m. on August 14 (within 2 hours), while the New York City Subway resumed limited services around 8 p.m.

Full power was restored to New York City and parts of Toronto on August 16.

At the time, it was the world’s second most widespread blackout in history, after the 1999 Southern Brazil blackout.