The New York City Fire Department said the cause of the outages, which have left more than 45,000 Con Edison customers without power, was a transformer fire which started at West 64th Street and West End Avenue.
The scene in Manhattan was one of confusion on Saturday evening, after the lights flickered off at around 7:20pm in Midtown, Hell's Kitchen, and large parts of the Upper West Side.
The electricity cuts come on the anniversary of a massive power failure in 1977 that plunged the NY skyline into darkness and triggered widespread looting and arson.
Power was out in much of Rockefeller Center. "That's what we noticed first", she said.
Officials with Con Edison later tweeted that they were working to restore electricity to customers and businesses primarily on Manhattan's Upper West Side. We will continue to provide updates as soon as we have more information.More news: Everyone’s sleeping on Amazon Music Unlimited
More news: President Trump is not a fan of Bitcoin or other cryptos
More news: EU signals sanctions on Turkey over Cyprus drilling
Mayor Bill de Blasio said on Twitter that the outage was caused by a "manhole fire", but later told CNN it was under investigation.
A Jennifer Lopez concert at Madison Square Garden was halted and disappointed fans had to be evacuated.
The cuts are affecting the Upper West Side of Manhattan between 40th and 72nd Streets between Fifth Avenue and the Hudson River, an area which includes the Broadway theatre district.
Screens in Times Square are black during a widespread power outage on Saturday in NY. It advised people to stay away from underground stations. She had planned to take the A train home when the power outage occurred.
The outage occurred on the 42nd anniversary of a NY blackout that crippled almost the entire city during a heat wave on July 13, 1977.