Funeral services for a veteran District fire lieutenant who died in the line of duty will be Friday at the D.C. Armory in Southeast Washington.

Lt. Kevin McRae, a 44-year-old husband and father of three, collapsed Wednesday after descending from a ninth floor apartment in a building at Seventh Street Northwest in Shaw, two blocks north of the convention center. He died later at a hospital. A fire department spokesman said Sunday that a cause of death has not been determined.

A public viewing will be held at 9 a.m. Friday at 2001 East Capitol Street SE. A public funeral service will start at 11 a.m. McRae will be interred at the Fort Lincoln Cemetery on Bladensburg Road in Brentwood, Md.

McRae, who joined the fire department through a high school cadet program in 1989, was the District’s 100th firefighter to die in the line of duty; his cousin, James J. McRae III, was the 99th. His cousin died of a heart attack while on duty in Tenleytown in 2007.

“Lt. McRae was a true hero,” Mayor Muriel E. Bowser (D) said in a statement Sunday announcing the funeral arrangements. “For more than two decades, he served his city with distinction and made the ultimate sacrifice while helping others.”

The fire broke out about 8:15 a.m. and burned out two apartments on the ninth and 10th floors of a sprawling L-shaped building in the 1300 block of Seventh Street NW. The building is filled with seniors and young families.

The cause of the fire has not been determined, said Tim Wilson, a spokesman for the D.C. Fire and Emergency Medical Services Department.

One of the displaced occupants, Ruby Morgan, 77, said last week that she heard a noise that seemed to be coming from the walls, or possibly a neighbor’s residence, on the ninth floor. She said she looked, and — at least initially — saw nothing. “Then,” she said, “it got so I couldn’t see at all.”

Smoke had apparently filled Morgan’s apartment, although the precise source was unclear. Morgan said she ran out into the hallway and began banging on neighbors’ doors, telling them to evacuate. She said a maintenance worker emerged from the elevator and she told him, “My apartment’s on fire.” A neighbor, she said, helped her down nine flights of stairs.