New York City firefighters work the scene of a large fire and a partial building collapse in the East Village neighborhood of New York on Thursday, March 26, 2015. Orange flames and black smoke are billowing from the facade and roof of the building near several New York University buildings. (AP Photo/John Minchillo)

NEW YORK, N.Y. - Firefighters used high-powered water towers Friday to extinguish pockets of fire at the site of an apparent gas explosion in Manhattan's trendy East Village as authorities reported that two people were missing and six others might be, too.

Nineteen people were injured, four critically, after the powerful blast and fire sent flames soaring and debris flying Thursday afternoon. Authorities said they were searching for Nicholas Figueroa, who had been on date at a restaurant in one of three buildings that were levelled, and Moises Lucon, a worker there.

Police said they also were trying to determine whether six other people reported missing — but not thought to have been in the destroyed buildings — were connected to the explosion.

Preliminary evidence suggested that a gas explosion amid plumbing and gas work inside the building was to blame. An hour before the blast, utility company inspectors decided the work being done there was faulty.

On Thursday night, Tyler Figueroa said his 23-year-old brother, Nicholas, had disappeared after going on a date at a sushi restaurant, whose building facade was still intact Friday.

Figueroa said that the couple was paying for the meal when the blast occurred and that his brother's date, who is in the hospital, remembers only stumbling outside before losing consciousness.

"I just pray my brother shows up," he said.

On Friday, firefighters poured water over the wreckage, a giant wave of crumbled brick, twisted metal, splintered wood and bits of residents' belongings. Rubble was still strewn across parked cars, and a menu from the sushi restaurant and other debris were scattered across the surrounding streets.

Initial evidence pointed to a gas explosion. A plumber was doing work connected to a gas service upgrade in one of the now-destroyed buildings, and inspectors for Con Edison had been there earlier Thursday, company President Craig Ivey said. But the work failed the inspection, partly because a space for the new meters wasn't big enough, Con Ed said.

Con Edison said it had surveyed the gas mains on the block Wednesday and found no leaks.

A woman listed in city records as the building's managing agent didn't immediately respond to messages Friday. An engineering firm involved in getting permits for work at the building declined to comment.

A contractor who was injured in the blast — and who's facing unrelated charges of bribing an undercover investigator posing as a housing inspector — declined through his lawyer to comment on the circumstances surrounding the explosion.

Police Chief of Detectives Robert Boyce said the contractor, Dilber Kukic had tried to help people escape the explosion and had been helpful to authorities.

News from © The Associated Press, 2015