New York City Mayor Bill de Blasio is directing unidentified city agencies to investigate what caused the widespread blackout in Manhattan Saturday night, according to his verified twitter account.
Power was restored to thousands of customers just after midnight.
Power has been restored to all customers, Con Edison CEO John McAvoy said, after a power outage in Manhattan left as many as 72,000 customers in the dark Saturday night.
This is not an infrastructure issue, New York Gov. Andrew Cuomo said.
"We were lucky tonight," Cuomo said.
The governor is urging drivers to stay off the road because many traffic lights are still out.
The thousands of customers without power in Manhattan Saturday included Carnegie Hall. Performers who were evacuated put on an impromptu show for passersby outside.
Con Ed says it has restored power to 62,000 customers on the West Side of Manhattan. About 10,000 customers remain without power, the company said.
Con Ed is working to restore power to those customers by midnight, it said.
The power outage affected about 72,000 customers at its height, the company's CEO said. The outage area stretched from West 72nd Street on the north, West 30th Street on the south, the Hudson River on the west and 5th Avenue on the east, Con Ed said.
People started cheering Saturday night when power was restored in some buildings in the city.
Authorities have said they don't have a good estimate as to how long it should take to restore power but John McAvoy, CEO of Con Edison, told reporters he doesn't expect additional outages this evening.
At The Knickerbocker Hotel in Manhattan, firefighters were working to help guests out of stuck elevators.
There have been no injuries or fatalities during the power outage, said New York City Emergency Management Commissioner Deanne Criswell during a news conference Saturday night.
Criswell says there is a task force comprised of members of the NYPD and FDNY that are going building-to-building to make sure nobody is trapped in an elevator.
New York Gov. Andrew Cuomo is calling up the national guard to help with traffic control in Manhattan, he told CNN's Ana Cabrera.
State Police will also be assisting.
Cuomo said traffic lights are out in "very busy intersections, and it can get chaotic very quickly."
New York Gov. Andrew Cuomo says he's directed law enforcement, city and transportation officials to respond to the power outage in the city.
"We are in constant communication with Con Ed, who has an effort underway to begin restoration of power by midnight tonight," Cuomo said in a press release.
No injuries have occurred as a result of the outage, Cuomo said, but called the incident "unacceptable."
"I am directing the Department of Public Service to investigate and identify the exact cause of the outages to help prevent an incident of this magnitude from happening again," he added.