Illegal work was being performed on gas lines in the East Village building where a massive explosion sparked a fire that destroyed it and two adjacent buildings, law-enforcement sources told The Post on Friday.
Authorities suspect construction workers had shut off illegal gas service inside 121 Second Ave. ahead of a Con Ed inspection Thursday, then restored it shortly before the blast, the law-enforcement sources said.
Homicide charges are now possible if anyone missing from the blast turns up dead.
“They could face criminally negligent homicide and, if reckless, [second-degree] manslaughter,” the source said.
Meanwhile, Mayor de Blasio said no one reported the ensuing gas leak to 911, even though the owner of a restaurant in the building that blew up had smelled gas shortly before the Thursday-afternoon blast.
“He called the landlord, is what we understand . . . and I understand that anyone might think that’s a common-sense thing to do. The point we have to get across is there’s no substitute for calling either 911 or Con Ed,” the mayor said. “The first call has to go to 911 or to Con Ed.”
NYPD Chief of Detectives Robert Boyce said: “There was no call to evacuate [by the restaurant owner] as far as we know right now.”
De Blasio said the latest count had 22 people injured, four critically. The 18 with less-serious injuries includes six firefighters.
No deaths have been confirmed, but cops were searching for two people reported missing in the Sushi Park eatery and one additional missing person who’s possibly connected to the blast.
A source in city government said that there were no active permits allowing any construction work in the building and that a renovation project approved in 2013 was fully completed last year.
Still, workers have been installing gas risers so the ground-floor business and four apartments could be individually metered.
That’s a job that requires gas service be shut off to the building, law-enforcement sources said — but tenants told cops there was gas service in the five-story former tenement at least a day before the blast, sources said.
“There’s no way they could have been getting gas in those apartments legally,” a source said.
Another source noted the “short period of time” between when Con Ed left the building, at around 2:45 p.m., and the blast, first reported to 911 at 3:17 p.m.
“The question is: Was this contractor illegally supplying gas to the apartments above before the Con Ed inspection?” the source said.
“Then they stop supplying the illegal gas when Con Ed comes to the location for the inspection. When Con Ed leaves, they start the gas up again and the explosion occurs a short time later. That’s one theory we have.”
Sources also said several city agencies were investigating Bronx contractor Dilber Kukic, owner of Neighborhood Construction Corp., who got a permit last year to do plumbing and other renovations at 121 Second Ave.
Kukic, 39, was among 50 people busted last month in a corruption scheme involving more than a dozen housing and building inspectors.
He allegedly paid $600 to fix housing-code violations at two buildings he owned in upper Manhattan.
His lawyer refused to comment on the investigations into Thursday’s blast.
“What happened yesterday is a horrible tragedy, and our thoughts are with the victims,” lawyer Mark Bederow said.
Authorities are also eyeing the possible role of plumber Jerry Ioannidis, who may have been working at the scene.
There was no answer at his Queens home Friday, and he couldn’t be reached by phone.
City records show a plumber who was licensed to work on the building last year was affiliated with Ioannidis as recently as 2012.
The same year, that plumber, Andrew Trombettas, was slapped with an unspecified fine and a year of probation by the city, according to records. It wasn’t clear what led to the penalties.
Also Friday, FDNY firefighter Mike Shepherd described springing into action while having lunch off-duty nearby.
Shepherd, 47, said he ran to the sound and saw bodies on the street, then immediately started looking for people trapped within the blast site.
With flames spreading, Shepherd, a third-generation firefighter, climbed the fire escape and searched the second, third and fourth floors.
The second floor was completely collapsed, he said.
By the time he reached the fourth floor, the fire intensified, and people on the street started screaming at him to get down.
The father of three shrugged off his heroism Friday, saying he wishes he could have done more.
“I’m a third-generation. Maybe it’s just in your blood,” Shepherd said. “Being a New Yorker, you’re always willing to go out and help somebody, you know?”
The Standard hotel had offered a free, three-night stay to those displaced by the blast, and a worker there said Friday that the entire place was booked up.
Additional reporting by Rebecca Rosenberg, Jennifer Bain, Ben Feuerherd, Lia Eustachewich and Bruce Golding