NEW YORK (CBSNewYork) – New York City lights can often be seen from miles away, but for 30 minutes Friday morning, nearly half of Manhattan went dark.

Midtown residents Joseph Negrelli said the blackout caused panic on the streets.

“We were crossing the street, and it’s like someone threw a light switch, and it went entirely black,” he told CBS2’s John Dias. “I moved to the side because I didn’t want to get run over by a car and waited until the lights came on.”

Con Edison said just after 5 a.m., three networks lost their electrical supply, impacting Harlem, the Upper East Side and Upper West Side.

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The disturbance had early risers uneasy, especially those working from home.

“I was worried that I wasn’t going to get my work done this morning and prepare for the stuff I’ve got to do,” said Elliott Scott, of the Upper West Side.

“My husband actually heard something click. The air conditioning went out,” Gloria Calden, of the Upper West Side, added.

In the suburbs, above ground electrical wires and trees are still down after Tropical Storm Isaias blew through on Tuesday. Thousands remain without power.

However, Con Ed said the Manhattan outage, where lines are underground, had nothing to do with the storm.

“We are investigating a problem on our transmission system that caused three networks in Manhattan to lose their electric supply at about 5:13 this morning. The supply has been restored to those networks on the Upper West Side, Harlem and the Upper East Side,” the utility said in a statement.

“Totally separate from the storm earlier in the week, there was an early morning outage affecting over 100,000 customers. That is a new outage,” Mayor Bill de Blasio said during his daily briefing. “It appears to have been weather related, there was weather activity last night. But all of those customers have been restored. So that was a very brief outage.”

Dias spoke with two grocery store managers who said they were concerned about business, already on the decline because of the pandemic.

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“Everything goes black, and nobody knows what is going on,” Efren Mones, manager of West Side Market, said. “It was a little freaky, because a lot of people go out for pandemic and they are not in the city, and then we had the blackout. We were afraid that we’re going to lose more business.”

They were also worried about the 70% of their merchandise that needs to be refrigerated.

“If it had happened, we had some bags of ice so we can put some frozen stuff. That’s a way we keep it,” said fellow manager Kotto Aboudou.”

Luckily for them and everyone else living uptown, service was restored later in the morning.