A three-story duplex in Philadelphia caught fire on Wednesday morning, leaving eight children and four adults dead in the city's deadliest fire in more than a century. 

Philadelphia officials have not identified the victims, but family members told FOX 29 Philadelphia that they ranged in age from 1-year-old to 33-years-old. Two of the victims were sisters who were also both mothers. 

"My sisters and my nieces and my nephews are gone, they are deceased, they are never coming back," Keta Purifoy, a relative of the victims, told the local news outlet. 

A family member released these photos of some of the victims of the house fire in Philadelphia on Wednesday morning.  (WTXF via Qaadira Purifoy)

The building, which was owned by the Philadelphia Housing Authority, had 26 people living in it – eight people in the first-floor unit and 18 people in the unit on the second and third floors.

PHILADELPHIA FIRE: FOUR SMOKE DETECTORS WERE NOT WORKING IN HOUSE FIRE THAT LEFT 12 DEAD 

The family that lost members to the fire originally moved in as a 6-person household in 2011 on the second and third floors, Philadelphia Housing Authority (PHA) President Kelvin Jeremiah said Thursday. 

"The family had children and the family grew," Jeremiah said at a press conference Thursday. "I want to make clear that this is a family that wanted to be together and our mission is to provide safe sanitary housing."

Philadelphia firefighters work at the scene of a deadly row house fire, Wednesday, Jan. 5, 2022, in the Fairmount neighborhood of Philadelphia. (AP Photo/Matt Rourke)

The fire started around 6:30 a.m. and a fire crew was on the scene by 6:40 a.m., where they found "heavy smoke, heat, and limited visibility on all floors," according to officials. 

One child was rescued from the building but did not survive. Several people were able to evacuate the home on their own and two individuals were taken to a local hospital for treatment. 

COLORADO FIRE: PARTIAL HUMAN REMAINS FOUND DURING SEARCH FOR TWO PEOPLE STILL MISSING

Four smoke detectors inside the duplex were not working at the time of the fire, Philadelphia Deputy Fire Commissioner Craig Murphy said. 

The two units inside the building, one on the first floor and one on the second and third floors, were last inspected in April and May of last year, and the smoke detectors were working at the time, according to the Philadelphia Housing Authority. 

"It was terrible. I’ve been around for 35 years now and this is probably one of the worst fires I have ever been to," Murphy said. 

CLICK HERE TO GET THE FOX NEWS APP 

The fire department was able to get the fire under control within an hour.