Aug. 7 (UPI) -- Large sections of New York City were briefly left without power early Friday, which delayed the subway system and trains at Grand Central Station in Manhattan.
Utility Con Edison said it was investigating "a problem on our transmission system" that caused three networks in Manhattan to lose power supplies a little after 5 a.m.
The outage covered large swaths of the city's Upper West Side, Harlem and Upper East Side, affecting more than 187,000 customers before power was mostly restored within an hour.
The outage caused disruptions on several heavily traveled subway lines, while train service on the Hudson, Harlem, New Haven lines through Grand Central Terminal saw delays as long as 15 minutes, the Metropolitan Transportation Authority said.
Con Edison said Friday it was working to restore electricity to about 122,000 homes and businesses in New York City and Westchester County.
The vast majority are expected to be restored by Sunday night.
"Thanks to the enormity of the workforce assigned to the job and the around-the-clock schedule. The remaining customers will get service back early next week," the utility said.
The widespread outage came as some of the city was still struggling to restore power after Tropical Storm Isaias passed through earlier this week. Nearly 4 million customers in the Northeast lost service.