On the evening of July 13, 1977, a severe thunderstorm swept through Westchester County, north of New York City. At 8:37 PM, a single lightning strike hit a critical 345-kilovolt substation at Buchanan South, adjacent to the Indian Point nuclear power plant on the Hudson River. The strike tripped a circuit breaker that disconnected a massive feeder carrying electric power from upstate generators into the city.
Moments later, a second lightning strike disabled two additional vital transmission lines. Consolidated Edison operators tried desperately to manually shed load and engage local power generation, but automated safety relays reacted faster than human operators could intervene. As power demands shifted rapidly across interconnected transmission corridors, neighboring power pools automatically severed connections to protect their own networks from collapse.
Isolated from external generation sources, New York City's internal turbines tripped off one by one due to extreme overloads. By 9:36 PM, the entire municipal electrical system had collapsed, plunging all five boroughs into complete darkness for over 25 hours. The resulting power outage triggered widespread civil unrest, arson, and looting, starkly highlighting the extreme vulnerability of complex urban power networks dependent on centralized long-distance transmission lines.