EAST COBB - Twenty people were burned out of their east Cobb apartment homes Wednesday morning after a fire started in a second-story unit.

Cobb firefighters responded at 7:55 a.m. to flames coming from the roof of the Signature Place apartment complex at the corner of Powers Ferry Road and Delk Road. Fire authorities said they suspect a furnace in an apartment unit caused the fire. Four units sustained heavy fire and smoke damage, and four others received minor damage, Cobb Fire reported.

A 16-year-old male complained of smoke inhalation, but refused to be taken to a hospital. One Cobb firefighter had problems breathing. He was transported to WellStar Kennestone Hospital in Marietta and released later in the day, Cobb Fire spokeswoman Denell Boyd said.

It took 30 minutes for firefighters to control the fire, Boyd said.

She said it was the second time in three days that the fire department responded to furnace problems at the apartment complex.

"We had a call that came in yesterday for the same thing," Boyd said. "They just said they had a smoke odor and we came out and couldn't find anything."

Residents said they complained about the odor Monday to Signature Place management, but management did nothing.

"These apartments - the outlets and all the electricity are no good," said Oscar Salanas, who lives in a nearby unit.

Signature Place manager Tammy Brusie declined to comment about the complaints.

Maselal Cardelas said she, her two young children and a friend lived in the apartment unit where the fire started. They all safely escaped after hearing a loud "boom" and saw fire, she said. She called the situation "scary."

The Red Cross was on the scene to assist the seven families who are displaced as a result of the fire. Don Krohn, a Red Cross volunteer, said the apartment complex's management team was able to find other units there for them to live in. He said the Red Cross provided food and clothing to the victims.

The National Weather Service reported that it was 23 degrees in Marietta on Wednesday morning, which Boyd said can cause issues with fighting fire.

"Sometimes we have an issue with hydrants and water, and (firefighters') hoses freezing up. But, today we were OK," Boyd said on Wednesday. "Obviously it makes it more difficult for the firefighters to fight fire in this weather because you're in that 1,200 degrees and you come out here and you're freezing."