In 1965, the biggest electricity grid failure in U.S. history caused a 13-hour blackout in northeast America and parts of Canada. The power lines from Niagara Falls to New York City were operating near their maximum capacity. At about 5:15 pm, a transmission line relay failed. Now there was insufficient line capacity for New York City. New England and New York are inter-connected on a power grid, and the power that had been flowing toward New York City had to go elswhere, instantly. Unable to handle this overload, generator operators shut down to protect their equipment. Almost the entire grid failed, affecting 80,000 square miles, and 25 million people. In the subways of New York, 800,000 people were trapped.[Image: New York City as seen from Broolyn during blackout from Life magazine Vol. 59 No. 2, 19 Nov 1965)