July 14 (UPI) -- Power company Con Edison is investigating why thousands of customers lost electricity for several hours in Midtown Manhattan amid calls by government officials to make sure another widespread blackout doesn't cripple the city again.
The blackout began about 7 p.m. Saturday night and most power had been restored to residents and businesses by midnight.
"All customers are back in service, we will focus on investigating the cause of the equipment failures and on getting the electrical-delivery system back to its normal level of reliability," Con Ed tweeted early Sunday morning.
Broadway shows and a Jennifer Lopez concert at Madison Square Garden were canceled Saturday night, and landmarks like the Empire State Building, Carnegie Hall and Radio City Music Hall all temporarily went dark.
The New York Post, which shared photos from social media of some of Times Square's huge, darkened video screens, reported a manhole fire impacted an underground transformer and sparked the outages, which happened on the anniversary of the 1977 New York City blackout.
"When we have an incident like this, we focus first on isolation of the failed equipment or the most likely failed equipment and then restoration of the customers, and then when customers are restored is when we really do the full root cause investigation to identify what may have caused it," Con Ed CEO John McAvoy said in a WCBS-TV report.
At the height of the blackout, about 71,000 customers out of 3.3 million in Manhattan lost power, according to Poweroutages.com.
The current population of New York City is estimated at 8.5 million.
"With the power back on, I've directed City agencies to investigate this evening's blackout. They'll work with ConEd to get to the bottom of what happened tonight and prevent another widespread outage like this," New York City Mayor Bill de Blasio tweeted from Iowa where he is campaigning for president. He returned home Saturday night.
Gov. Andrew Cuomo said the darkened streets and buildings caused a "dangerous" situation.
"You just can't have a power outage of this magnitude in this city," he said. "The potential for public safety risk and chaos is too high. We just can't have a system that does this."
"Con Ed has improved, but they still have to do a lot more," Schumer said. " That is good. On the other hand, it shouldn't happen at all, and god forbid if someone were stuck in an elevator and had a heart attack or a stroke and couldn't get out of that elevator, things would have been worse. Thank god that didn't happen, but we cannot have these blackouts in cities as densely populated as ours. Is Con Ed putting in all the money to upgrade its infrastructure ... so these don't happen again? They are happening with less frequency and this was restored quickly. That's better, but not good enough."
The Senate minority leader also wants the Small Business Administration to look into reimbursing restaurants and small business owners who might have lost money during the incident.
He thanked New York's police and fire departments "for all you're doing yo help New Yorkers" on a Twitter post.