1965: The biggest electricity grid failure in U.S. history causes a 13-hour blackout in northeast America and parts of Canada. Due to a transmission line failing between Niagra Falls and New York City, almost an entire grid failed, affecting 80,000 square miles including New York City and New England, and 30 million people. In the subways of New York, 800,000 people were trapped. By midnight, more than 90 percent of subway passengers had been freed. By 4:44 a.m. the next day, power was restored to Manhattan.