The FDNY is mourning the loss of one of its own after a Williamsburg apartment building went up in flames Saturday night.

Lt. Gordon Ambelas, also known as Matt, suffered multiple injuries when he became trapped while looking for victims in a high-rise apartment at the Independent Towers complex, where a two-alarm fire had broken out at around 9:30 p.m.

Fire Commissioner Daniel Nigro says Ambelas was found unconscious on the 19th floor of the building. He was removed by fellow firefighters and later died at the hospital.

Two other firefighters were taken to Bellevue Hospital with minor injuries and two people received medical treatment at the scene.

News 12 is told Ambelas was promoted to lieutenant 10 months ago at Ladder 119.

He worked alongside fellow firefighters during the recovery efforts of 911, and assisted in Hurricane Sandy relief.

Ambelas, who was a 14-year veteran of the force, is the first firefighter to die in the line of duty in more than two years.

He is survived by his wife and two daughters, ages 5 and 8.

Mayor Bill de Blasio hailed Ambelas as a hero and asked New Yorkers to keep his family in their prayers.