MILWAUKEE, Wis. (AP) — Three men died early Wednesday when a fire swept a Milwaukee home that apparently lacked a working smoke detector, authorities said.

The identities of all three victims have not been confirmed, but Milwaukee Fire Chief Aaron Lipsky said it’s believed they were a father, age 83, and two sons ages 53 and 57.

All three were found on the first floor of the home on the city’s north side. Deputy Fire Chief Erich Roden said two were hospitalized before succumbing to their injuries, while the third was pronounced dead at the scene.

Lipsky said the cause of the fire, which was reported about 4:30 a.m. CDT., has not been determined, but it likely started due to an appliance or utility because the origin point was located in the basement near the furnace and water heater.

Lipski said the home did not appear to have a working smoke detector in place. He and Mayor Cavalier Johnson stressed that a working smoke detector could have played a critical role in controlling the fire and saving the men’s lives.

Mike Thornton, 37, who lives across the street from the home, said the 83-year-old man had lived on the block for around 20 years.

“It’s sad,” he told the Milwaukee Journal Sentinel. “He was a nice person. He would talk to everyone.”