NEW YORK — A power failure plunged a stretch of the West Side of Manhattan into darkness Saturday night, trapping people in subway cars and elevators for a time, leaving drivers to fend for themselves at intersections with no traffic signals and eerily dimming the lights in a swath of Times Square.
Stores emptied out, and Broadway shows did not go on: Most theaters canceled their performances. In restaurants and bars, people drank by the glow of their smartphones.
But the lights — and, on a warm Saturday night in midsummer, the air conditioning and fans that keep people cool — began to return about 10 p.m. Power was fully restored by midnight, with cheers ringing out on the streets in response.
Con Edison said that the power failed at 6:47 p.m. and that 73,000 customers were in the dark for at least three hours, mainly on the West Side. The blackout stretched from 72nd Street to the West 40s, and from Fifth Avenue to the Hudson River.
Con Edison said the failure apparently stemmed from a problem at a substation on West 49th Street and affected six power sectors.
John McAvoy, Con Edison’s chairman and chief executive, suggested it was a mechanical failure but emphasized that the utility would not know the cause until an investigation was completed.
Gov. Andrew Cuomo was more specific, saying the failure started with an explosion and fire at a substation that caused other substations to “lose power and malfunction.”
“Once we get past the emergency, then I want to know what the heck happened,” Cuomo told WABC-TV, “because this is not the first time we have had a substation issue.”
Mayor Bill de Blasio, who was in Iowa campaigning for his presidential bid, ruled out terrorism or criminal activity.
Con Edison customers “expect to have a system that contemplates, anticipates and prevents foreseeable occurrences,” he said.
The blackout happened on the same date that a large power failure in 1977 plunged the city into darkness. (Now as then, Times Square — usually blindingly bright with crowds strolling to theaters — was dark, and traffic signals were out.)
At intersections, police officers and civilians worked together to direct traffic while firetrucks and ambulances screamed down side streets. Two young women posed for a selfie in the middle of 46th Street before an officer rushed over and chastised them, saying, “Ladies, this is not the time.”
The Metropolitan Transportation Authority, which runs the subway, said the blackout affected the entire system, with limited service for a time on several lines.
Ellie Shanahan, 23, was on the A train between West 50th and 59th streets when the train stopped unexpectedly. She waited with the other passengers for nearly 20 minutes before an MTA worker announced that there was a power outage and that there would be no train service between 59th and 163rd streets.
After evacuating the subway station, she said, she noticed police officers trying to monitor the frantic crowds at West 50th Street.
She got on a Citi Bike and rode it to 125th Street.
“What was craziest to me was there were no traffic lights,” Shanahan said. “I was in shock, but people still seemed to know what to do. Everyone was being polite, even though there were no lights to tell us when to go.”
Most Broadway shows — including “Moulin Rouge! The Musical,” “Hadestown,” “Harry Potter and the Cursed Child” and “Aladdin” — canceled their performances.
On the sidewalks outside the theaters, the casts staged impromptu outdoor shows. Performers from “Waitress” and “Come From Away” sang versions of songs from their shows, and actors from “Hadestown” improvised a blackout-themed rendition of one of its songs.
Carnegie Hall canceled all performances Saturday night. At Lincoln Center, a performance from the Mark Morris Dance Group was canceled, but outside, the Midsummer Night Swing band kept going.
At the Jennifer Lopez birthday-themed extravaganza at Madison Square Garden, the power failure happened during the fourth song. The lights had been shining and the bass had been thumping and the opening notes of “Dinero,” Lopez’s hit Latin pop song, had sounded. A crew of dancers was onstage.
Suddenly, the lights went dark, and the speakers fell silent. The only sound was a live drum set, still playing as dancers continued their routine.
It soon became apparent that this was not part of the show.
Lopez appeared on the stage and seemed to be speaking. But with her microphone out, her message could not be heard.
After a while, a backup generator kicked in, and the lights came on. Minutes after that, a high-pitched chime sounded, and the audience was told to leave.
In the darkness outside, some fans were frustrated.
“I’ve waited my whole life to see Jennifer Lopez, and I didn’t get to see but five minutes of it,” said Jennifer Walker, 35, of Brentwood, New York.