When the manager of Sushi Park, a restaurant in the East Village that wasdestroyed Thursday in an explosion and fire, alerted the building’s landlord that afternoon to an odor of gas, it was not the first time that people who worked there had been concerned about how gas was flowing into the building.
The restaurant’s owner, Hyeonil Kim, 59, said in an interview on Friday that he had wondered how the apartments upstairs in the five-story building at 121 Second Avenue had been getting hot water and gas for cooking. The only gas line coming into the building had been dedicated to his restaurant, he said.
“I don’t believe that there was no gas at 121 during this winter season,” Mr. Kim said, speaking in Korean. “Somehow they got the gas, but how?”
Mr. Kim said he believed tenants had started moving into the building’s upstairs floors last summer, after the landlord, Maria Hrynenko, completed renovations. He said he suspected they were getting their gas from the neighboring building, 119 Second Avenue, which city records show is also owned by Ms. Hrynenko. She did not return calls for comment on Friday. Mayor Bill de Blasio suggested at a news conference on Friday that city officials had a similar suspicion.
The mayor said “a variety of sources” had led city officials to believe that the cause of the explosion might be traced back to the inappropriate accessing of a line that fed gas into one of the buildings. “There’s certainly a possibility of impropriety,” Mr. de Blasio said.
The building at 121 Second Avenue had been getting gas for cooking and hot water through a small pipe connected to a large gas main under the street, said Michael Clendenin, a spokesman for Con Edison. The utility had installed a larger connection to that main so that the building could receive enough gas to supply the apartments as well as the restaurant, Mr. Clendenin said.
Two inspectors from Con Edison came to the building Thursday afternoon, about a half-hour before the explosion, to inspect the plumbing work leading to the new connection. They did not detect any sign of a gas leak while they were in the building, said Carlos Torres, Con Edison’s vice president for emergency management. They did, however, find fault with the plumber’s work, determining that sufficient space had not been left for the new meter, Con Edison officials said.
Because of that, Mr. Clendenin said, the inspectors left without unlocking a valve that would have allowed gas to flow through the new pipe. Gas did continue to flow through the older pipe.
In a statement released late Friday, Con Edison said that its records showed that “the work of the building’s plumber failed two inspections, including the inspection our personnel conducted yesterday afternoon.”
It is unclear exactly what happened next in the building’s basement.
It was someone from the sushi restaurant who first detected a possible gas leak, at about 3 p.m., shortly after the Con Edison workers left, city officials said. He called the landlord, Ms. Hrynenko, and she sent her son, Michael, to check for the possible leak, the officials said. Mr. Hrynenko and a general contractor, Dilber Kukic, opened the door to the basement, just as the explosion occurred, they said.
Department of Buildings records show that plumbing work, which can include gas line work, was approved at the site from August through November 2014, said Stewart D. O’Brien, executive director of thePlumbing Foundation City of New York, a trade group.
The plumber on the job certified that the work met code standards in August 2014. City officials said that work was signed off on Sept. 25, 2014, and that any further work would not have been allowed without a new permit, which was not obtained. It is not clear from the records what work was being performed in the building, or whether it was being done by a licensed master plumber.
“All we know is that there was no approval from D.O.B. to do any plumbing work in that building after November 2014,” said Mr. O’Brien, a former Department of Buildings commissioner.
Andrew Trombettas is the licensed master plumber who performed the work on the site last year and whose name appeared on the building permit. Asked on Friday in a telephone interview whether he had been to the site since he completed his work last year, Mr. Trombettas said: “Never.”
“We don’t know who was there yesterday,” said Mr. Trombettas, who refused to answer more questions and could not be reached later. “We don’t know what happened. Whatever is going on, we’re not aware of.”
City building records show that Mr. Kukic, 39, a general contractor at the Bronx firm Neighborhood Construction, had been working on the building.
Mr. Kukic had hired a subcontractor, Robert K. Boyce, chief of detectives for the New York Police Department, said at a news conference on Friday. Police officials, speaking on condition of anonymity because of the ongoing investigation, offered two different spellings for the subcontractor’s name.
Searches of available public records did not yield plumbers by either of those names, but a close approximation appeared in a 2010 online advertisement, which identified a Jerry Ioannidis, the owner of Beta Plumbing & Heating Corp. in Astoria. And in 2012, records show, a disciplinary action initiated by the Department of Buildings against Mr. Trombettas identified one of his companies as Beta Plumbing & Heating Corp. Mr. Ioannidis is not licensed as a master plumber, a requirement for doing gas line work, according to city records. A telephone message left at his home Friday was not immediately returned.
Chief Boyce characterized Mr. Kukic as “very helpful” so far and said that he was not presently under investigation in connection with the blast.
In February, Mr. Kukic was charged by the Manhattan district attorney’s office with bribing an undercover investigator posing as a housing inspector. The case was part of a broader inquiry by the city Department of Investigation and the rackets bureau of the district attorney’s office. Prosecutors said Mr. Kukic had paid the undercover agent $600 in cash to dismiss violations at two properties he owned on West 173rd Street in Manhattan. He has pleaded not guilty and the case is continuing.
Mr. Kukic could not be reached for comment, but he told the news site DNAInfo.com what happened when he and Mr. Hrynenko went to the basement to check on the gas odor.
“As soon as we opened the basement door, there was an explosion, a fire,” Mr. Kukic told DNAInfo in a phone interview from NewYork-Presbyterian/Weill Cornell Medical Center, where he was being treated for burns and smoke inhalation.
No one contacted Con Edison about the smell, according to the utility. Since a gas explosion in East Harlem killed eight people last March, Con Edison and city officials have urged New Yorkers to call 911 immediately if they smell the rotten egg odor that indicates leaking gas. A movement as simple as turning on a light or opening a door, can cause an explosion, according to experts.