🔗 Northeast blackout of 2003

🔗 North America 🔗 Energy

The Northeast blackout of 2003 was a widespread power outage throughout parts of the Northeastern and Midwestern United States, and the Canadian province of Ontario on August 14–28, 2003, beginning just after 4:10 p.m. EDT.

Some power was restored by 11 p.m. Most did not get their power back until two days later. In other areas, it took nearly a week or two for power to be restored. At the time, it was the world's second most widespread blackout in history, after the 1999 Southern Brazil blackout. The outage, which was much more widespread than the Northeast blackout of 1965, affected an estimated 10 million people in southern and central Ontario, and 45 million people in eight U.S. states.

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 the entire Northeast region.