The 1965 Northeast blackout

California’s rolling blackouts in 2001 sent pundits harking back to the great 1965 Northeast blackout. But reckless deregulation, market manipulation and artificial shortages did not figure there as in California. Instead, the causes were technical-and stemmed from efforts to prevent shortages and blackouts. When electricity usage soared in the 1950s, power companies sought to ensure supplies by joining New York, New England and Ontario in a vast grid. When demand spiked in one locale, others would fill it. But in a twist that illustrates just how difficult it can be to predict how vast, complex networks will actually work, the engineers didn’t anticipate the effects surging supply in one area might have on others-effects that brought the whole grid down. The trigger was a single relay switch on a line bearing power from Niagara to Ontario, which had been set to trip off if power surged past a certain level. On Nov. 9, 1965, the power load exceeded that level, the switch tripped off-and the power that would have flowed to Toronto surged back into western New York, swamping the lines and causing generators to shut off to avoid getting fried. The cycle spread, south to New York City and east to the Maine border. Thirty million people across 207,200 square kilometers were cast into darkness. New Yorkers, who afterward claimed the regionwide blackout as their own, muddled through peaceably-dining out by candlelight, sleeping by the thousands in hotel lobbies, helping strangers. But one famed outcome-a baby boom nine months later-proved to be just legend.