On August 14, 2003, a series of faults caused by tree branches touching power lines in Ohio, which were then complicated by human error, software issues, and equipment failures, led to the most widespread blackout in North American history. More than 50 million people across eight northeastern U.S. states and parts of Canada were left without power for at least 24 hours, and many of them were in the dark for weeks. In New York City, thousands of commuters were stranded when the power cut out late on a Thursday afternoon. Memories of the 9/11 attacks only two years earlier were fresh in people’s minds as scenes of thousands of people evacuating Manhattan on foot were replayed.