Power Goes Out, Very Briefly, in Parts of New York City

A momentary power outage caused lights to flicker across parts of New York City late Thursday night, the authorities said, followed by what witnesses described as an explosion and rising smoke at an electrical substation in Brooklyn.

Con Edison, the electricity, gas and steam utility that services New York City and Westchester County, said there had been “a fault on a high-tension transmission line” at its substation in Brooklyn at 11:55 p.m.

“Customers may have experienced a dip or surge in power at that time,” Con Edison said in a statement early Friday. “Crews are investigating and working to make necessary repairs.”

The New York Fire Department said that firefighters were responding to power outages and stuck elevators at locations across the city early Friday.

“We don’t have a single address that we can narrow it down to,” the Fire Department said in a statement, adding that they were fielding “reports and calls at various locations.”

All elevators and escalators at Grand Central Station were out of service, according to a statement from Long Island Rail Road, the rail system that stretches from Manhattan to the eastern tip of Suffolk County on Long Island.

Witnesses with a view of the substation described the lights in their apartments as quickly blinking twice, followed by the explosion at the substation. People shared their accounts of the outage and the blast on social media.

“The lights flickered twice briefly,” Sean Scott, 30, a software engineer who was at home in Manhattan, said by telephone. “I looked outside and I saw some streetlights flickering.”

“Then I felt a soft boom and saw a fireball and I saw the smoke,” added Mr. Scott, who said he had a view of most of Brooklyn from his apartment.

Anna Di, 32, a chiropractor in Manhattan, described the explosion as an “orange glow” that disappeared within seconds, leaving gray smoke that rose from the substation.

“It was just shocking to see this ball of fire across the water,” she said by telephone.