(AP) -- Thousands of uniformed firefighters from across the country gathered Thursday for the funeral of a fireman labeled "a true hero" by the mayor.

Lt. Gordon "Matt" Ambelas died Saturday night searching for victims in a burning, cluttered Brooklyn high-rise apartment building. His was the first Fire Department of New York line-of-duty death in more than two years.

Mayor Bill de Blasio said during his eulogy that the 40-year-old FDNY veteran was dedicated, hardworking, kind and, above all, a family man. That theme was poignantly accentuated when fire helmets from Ambelas' old commands were placed on the heads of his daughters Gabriella, 8, and Giavanna, 5.

While "no one feels it more than the family that has suffered this loss," said the mayor, "all members of the FDNY -- but really, all New Yorkers -- are feeling this moment with pain and sadness, because we've lost a true hero."

The captain of his former command, Jerry Tucker, remembered Ambelas as a modest man with tremendous patience, who would help his young girls untangle fishing lines during camping trips.

In prepared remarks read by a tearful friend, his widow, Nanette, questioned just how exactly she could now live without her partner of 10 years, who was happiest with a cold Sam Adams in his hand, listening to Metallica and surrounded by his wife, daughters and friends.

"When I look at Gabbie and Gia I will see your smile," Margaret Gulliksen read from Nanette Ambelas' statement.

Ambelas had been promoted to lieutenant 10 months ago. Throughout his career he helped the city through its darkest hours, including the recovery from the Sept. 11, 2001, terrorist attacks and Superstorm Sandy.

Just weeks before his death from burns and smoke inhalation, he was recognized for helping to save a 7-year-old boy who became trapped in a roll-down gate in May.

Firefighters from Boston, Philadelphia and St. Louis were among those who traveled great distances to salute Ameblas' casket. It was lowered from a caisson draped in a department flag and taken into a Staten Island church by pallbearers, followed by his wife and their little girls.

Afterward, the firefighters were lined up for miles as he was transported for a private burial. Bagpipers and drummers dressed in kilts and berets lead the procession, playing "America the Beautiful."