A roof collapsed during a fire Wednesday night in the Lawndale neighborhood on the West Side.

The fire broke out in a two-story residence with five adults and one child inside about 9:10 p.m. in the 1200 block of South Millard, according to the Chicago Fire Department.

Firefighters responded to the still and box alarm and found a fire raging in the rear of the building on the first and second floor. The blaze was put out by 9:39 p.m., officials said, but started again about midnight.

The Chicago Building Department was called in due to reports of “a dangerous and open building with bad back porches,” the department said in a statement on Twitter.

The fire department’s Office of Fire Investigations has since determined that the fire was “incendiary,” meaning they found enough evidence to pass the investigation along to CPD arson detectives to look into the cause, CFD spokesman Larry Merritt said.

Firefighters responded to a fire about 9:10 p.m. in the 1200 block of South Millard. | Justin Jackson/ Sun-Times

The fire investigation was classified as a non-criminal as of Friday afternoon, police said.

No injuries were reported and the Department of Human Services responded to assist the six residents who were displaced.