NEW YORK — A blaze at a high-rise apartment that killed a fire lieutenant started in an air-conditioner electrical cord pinched between a bed frame and a wall, the fire commissioner said Sunday, adding that the fire had been ruled accidental.
Lieutenant Gordon Ambelas died late Saturday after suffering multiple injuries while on the 19th floor of the 21-story building in the Williamsburg section of Brooklyn, officials said. His was the Fire Department of New York’s first line-of-duty death in more than two years.
Firefighters solemnly hung flag bunting at the Brooklyn firehouse where Ambelas had worked for the last several months of his 14-year career. Ambelas, a 40-year-old married father of two daughters from Staten Island, had been promoted to lieutenant 10 months ago.
‘‘He died a hero — that’s how he lived,’’ firefighter Eric Bischoff said of his longtime colleague, friend, and former roommate, calling Ambelas ‘‘truly one of the best human beings that anyone would ever want to meet.’’
The fire broke out around 9:30 p.m. Saturday in an apartment on the 19th floor of the building, which is part of the six-building Independence Towers complex, owned by the New York City Housing Authority. Flames spread to the 17th and 18th floors.
‘‘Ambelas went into the apartment to search for life and did not come out, and by the time his brother firefighters found him, it was too late for him,’’ said Fire Commissioner Daniel Nigro.
The apartment was crowded with belongings, making searches difficult, the Fire Department said.
Fellow firefighters found Ambelas unconscious and carried him out of the building. They worked with emergency rescuers to try to revive him, but he died at a hospital, Mayor Bill de Blasio said.
‘‘New York City and the FDNY suffered a terrible and tragic loss,’’ he said.
Two other firefighters and two residents were treated for minor injuries.
The Housing Authority said in a statement Sunday that it was working with firefighters on the investigation . The agency did not answer questions about what fire prevention devices might have been in the apartment.