Much of Manhattan came to a standstill on Saturday night when a major blackout left thousands without power, shut down Broadway shows, left some people trapped in elevators, and forced ordinary New Yorkers to direct chaotic traffic—all on the 42nd anniversary of the 1977 New York City blackout.

By around 10:30 p.m., power started coming back on in some areas, and after midnight, Con Ed said it had been restored to all of the up to 73,000 customers affected. Dozens of pedestrians in one neighborhood let out ecstatic cheers and applauded, along with passing drivers, when the street was suddenly illuminated again as they struggled to cross a pitch-black road.

The relief came after hours of mayhem across the Upper West Side after subway stations were abruptly plunged into darkness, the Rockefeller Center was left in the dark, and parts of Time Square shut off due to what Gov. Andrew Cuomo described as an “issue with a transmission line.”

A person with direct knowledge of the incident told The Daily Beast that a transformer fire on West End Avenue and West 64th Street on the Upper West Side of Manhattan was among the reasons for the blackout.

Cuomo ordered an investigation into the incident late Saturday “to help prevent an incident of this magnitude from happening again,” he said in a statement. “While fortunately no injuries occurred as a result of this incident, the fact that it happened at all is unacceptable,” he said, noting that the Department of Public Service had been tasked with determining the “exact cause” of the blackout.

Mayor Bill de Blasio, campaigning in Iowa, called the outage a “mechanical issue” and stopped short of committing to return to the city, saying only that he would adjust his schedule depending on what he learns from emergency officials about the blackout.

Meanwhile, ordinary New Yorkers rose to the occasion and seized control as best they could, even planting themselves in busy intersections to direct traffic where the lights had failed.

One of the heroes of the night was Angel Coria, a 57-year-old off-duty tow truck driver who stood at W 41st Street and 10th Avenue in a darkened intersection jammed with cars and buses, emergency vehicles and pedestrians. He lit a flare and stood with it in his bare right hand, waving vehicles through one way while stopping them the other, and providing safe passage to pedestrians who called out their thanks.

The danger was considerable given the lack of light and the crush of vehicles; nobody was hurt.

“You have to,” he said when asked why he stepped in.

He stopped after 90 minutes, the flares spent, having been assisted for a while by a Daily Beast reporter.

“I want to be away from everybody on a fishing boat,” he said as he left.

The New York City Fire Department said they had units responding to various calls from every borough of New York, with multiple reports of stuck elevators and multiple transformers in the area smoking.

Fire vehicles were dispatched from all over the city, including Ladder 114 from Brooklyn, where a firefighter echoed what firefighters have long been saying: The city’s electrical infrastructure is decrepit and not up to the demands of the tech age.

“It was not even that hot and humid,” he said. Looking at the dark buildings, he said, “There's a lot of elevators. We're hoping to see some lights coming on.”

Some residents said they had issues getting through to the fire department when calling 911, and at least one person had to walk to the nearest fire station to get help.

The power went out just as the curtains were about to go up on Broadway shows, and thousands of theater-goers disgorged into the streets as performances were postponed or cancelled.

But some performances went on anyways—in the street. The cast of Broadway musical Hadestown performed songs on the sidewalk outside the theater for a growing crowd of fans after the power outage disrupted their show.

A concert at Carnegie Hall halted by the blackout also got its own impromptu outdoor rendition in the street.