At 8:37 PM on July 13, 1977, a severe thunderstorm swept across Westchester County, New York. A bolt of lightning struck a 345-kilovolt substation at Buchanan South, directly tied to the Indian Point Nuclear Generating Station. The bolt tripped two major circuit breakers, isolating the Indian Point No.
3 nuclear unit and cutting off a crucial supply of power to New York City. Automatically, protective systems attempted to reclose the breakers, but a secondary fault prevented the system from stabilizing. Con Edison operators in Manhattan were suddenly forced to handle a massive generation deficit.
As automatic safeguards failed and human operators delayed manual load-shedding to prevent rolling brownouts, neighboring power grids picked up the slack until their own automatic breakers tripped from overload. Within 45 minutes, a second lightning strike hit another critical line, causing a complete system collapse. By 9:27 PM, all of New York City was plunged into darkness, leading to widespread looting, fires, and economic chaos across the five boroughs.