A massive explosion that rocked New York City's East Village and injured at least 22 people Thursday may have been caused by someone "inappropriately" accessing a gas line in the the building, Mayor Bill de Blasio said Friday.
Just minutes before the blast, the mayor said, the owner of a restaurant on the building's ground floor had called his landlord to report smelling gas.
At a news conference Friday, De Blasio said preliminary information indicated that someone in the building could have accessed a gas line without authorization.
The explosion leveled the building and caused two others to collapse.
Heavy debris and the still-smoldering ashes of the blaze that followed the explosion have prevented investigators from entering the site, De Blasio said.
"Until we can see it with our own eyes, it would be unwise to speculate too much," he said.
"You rarely see such a scene of devastation in the middle of a city like this," De Blasio told reporters. "This was, 24 hours ago, a vibrant bustling street, and today people are dealing with the aftermath of this tragedy."
Two men remained unaccounted for Friday, said Robert Boyce, chief of detectives for the New York Police Department.
A law enforcement official with knowledge of the investigation identified them as Nicholas Figueroa, 23, and Moises Lucan, who is believed to be in his 20s. According to Boyce, witnesses said the men had been inside the Sushi Park restaurant at the time of the blast, and police are still trying to locate them.
Figueroa had paid his bill at the sushi restaurant and was about to leave, family members told the Associated Press.
Figueroa was on a lunchtime date, family members told the New York Times, and the woman he was with is being treated at a nearby hospital.
Little was known about Lucan.
A third person remains unaccounted for, but investigators don't believe the individual was inside when the explosion happened.
De Blasio said Friday that 22 people were injured, including six members of the New York Fire Department. Police and fire officials had previously put the number at 25; the reason for the discrepancy was unclear. Four were critically injured, De Blasio said.
Two of the critically injured were taken to Bellevue Hospital, a Fire Department spokeswoman said Thursday. As of Friday morning, three patients were being treated there, a hospital official said: a 32-year-old man who was in fair condition, a 21-year-old man in serious condition, and a 23-year-old woman in fair condition.
Officials previously thought the explosion might have been set off by plumbing and gas work at the building Thursday.
On Friday, De Blasio said officials had no information about any work being done in the building that day, and that no permits for such work had been filed with the city. Inspectors with the gas company had just left about a half hour before the blast, after meeting with two contractors to inspect previous work on the building, according to a timeline released by Boyce.
Fifteen minutes later, the owner of the sushi restaurant on the ground floor called the building's owner to report smelling gas,
A short while later, Boyce said, one of the contractors and the building owner's son were walking into the basement and opened a door when the explosion occurred.
"There's just no holding back," De Blasio said. "The second you smell gas you have to call 911 or [the gas company]."
The blast caused three buildings to collapse, and caused significant damage to a fourth, officials said. Firefighters were still on the scene Friday morning, working to extinguish a "still active fire," according to information released by fire officials.
Staff writers James Queally and Tina Susman contributed to this report.