News NYC blackout caused by relay system failure, Con Edison says A large section of Manhattan's Upper West Side and Midtown neighborhoods are seen in darkness from above during a major power outage on July 13, 2019 in New York City. Photo Credit: Getty Images/Scott Heins By Ivan Pereira firstname.lastname@example.org @IvanPer4 Updated July 15, 2019 7:33 PM Print Share fbShare Tweet Email Con Edison revealed Monday afternoon that a malfunctioning protection system for parts of the electrical grid may have been the root cause for Saturday’s blackout that affected 72,000 Manhattan customers. The utility offered the initial findings of its investigation into the blackout, which took out power for the Upper West Side and midtown, and said the relay protection system at its West 65th Street substation failed to contain a 13,000-volt distribution cable that stopped working Saturday night. The protection system, “detects electrical faults and directs circuit breakers to isolate,” however, it didn’t work when the cable stopped working, according to the utility. “The failure of the protective relay systems ultimately resulted in isolation of the fault at the West 49th Street transmission substation, and the subsequent loss of several electrical networks, starting at 6:47 p.m.” Con Ed said in a statement. The utility said it was able to restore power quickly to the affected parts of Manhattan, by midnight, and immediately began its investigation. Con Ed said it is still investigating the incident and will provide more information when it becomes available. Several elected officials, including Mayor Bill de Blasio and Gov. Andrew M. Cuomo, have called for an independent investigation into Con Ed to determine how the blackout was able to affect such a large portion of the city. "While I appreciate that Con Edison released their preliminary findings so quickly, I am troubled that one of the few factors Con Edison initially ruled out, the 13,000-volt cable, has been determined to be the catalyst of the outage," de Blasio said in response to Con Ed's update Monday. "Our city cannot be left in the dark like this ever again, and we will continue to push Con Edison for a full accounting of this incident to ensure they are taking necessary steps to protect all New Yorkers." Cuomo gave several media interviews Monday to express his frustration with the utility. He told WNYC’s Brian Lehrer that the blackout was a serious public safety risk and he threatened to issue fines to Con Ed or revoke its franchise. “This is not a God-given right, and if they don’t perform well, they can be replaced,” he said. By Ivan Pereira email@example.com @IvanPer4 Ivan has been a staff reporter with amNewYork since May 2012 and covers breaking news, politics and enterprise stories. Share on Facebook Share on Twitter More on this topic A brief history of NYC blackoutsThe five-hour blackout on Saturday was not the first to hit the city, nor was it the biggest. Scenes from Saturday's power outage in ManhattanThe outage stretched from Fifth Avenue to the Hudson River and from West 42nd Street to West 72nd Street. Power restored but blackout questions remainCon Edison had few answers for why the power went out and what can be done to prevent another outage. Comments We're revamping our Comments section. Learn more and share your input.