A manhole explosion sent thick black smoke billowing into the air in midtown Tuesday and caused at least one building to lose power for half a day, authorities said.

Fire spewed from the manhole on 37th Street between Seventh and Eighth Avenues after the explosion around 9:30 a.m., officials said. No injuries were reported and no evacuations were ordered.

Video taken from a building above the fire showed black smoke wafting from a flaming pit on the sidewalk near two cars. Firefighters and police escorted bystanders to safety as plumes of smoke filled the street.

The fire blazed for several hours before authorities got it under control.

Lielle Kitchings, of Harlem, said he heard the manhole cover "popping."

"I see flames shooting out of the ground and the smoke is very heavy. People were running," Kitchings said, adding it reminded him of a scene from the movie "Wizard of Oz."

He said he was nervous because, as he watched the flames, he felt the ground rumble beneath him.

"I'm hearing the pops and I'm standing behind the door like, 'Oh my God, if it explodes I want to make sure this door protects me. Fire just kept shooting out," Kitchings said.

Several buildings were left without power for a time, including a high-rise in the area, as authorities responded. One building had no power for about eight hours.

Con Edison said it believed road salt from the winter brought down by rain last week got into frayed wire and caused the explosion, but the investigation is ongoing. A rat may also have gnawed at the wire, allowing the salt to seep in, the utility said.

Part of 37th Street was shut down as authorities investigated.