When was the largest power failure in US history?
The largest power failure in US history came on August 14, 2003. The power outage occurred in the northeastern part of the country. It was ultimately caused by an electrical problem in Ohio and a series of human errors to recover from the problem.
This was the largest blackout in history. Eight U.S states and two Canadian provinces were affected by the 2003 power outage. About 50 million people were left without power. 70,000 megawatts of power were lost. To put that in perspective, a million watts equals one megawatt. One megawatt can power a thousand households.