Firefighters were called to battle a three-alarm fire early Thursday morning in Pittsburgh's North Side neighborhood.
Crews said the blaze on Peralta Street was reported just before 4 a.m.
When firefighters arrived, they said flames were shooting out of the door and window of the building. Crews said the home was converted into a duplex with four apartments.
"There was lots of fire showing at the first floor, coming from the front door and windows," said deputy chief Frank Large.
Fire investigators said a space heater placed next to a couch may have caused the blaze. Officials said that smoking or candles could have also contributed to the fire.
One resident was taken to the hospital for smoke inhalation and a firefighter was hurt after he twisted his leg battling the blaze, officials said.
Seven people, including a 7-year-old child escaped the burning building unharmed.
One man who lives on the first floor was taken to a nearby hospital to be treated for smoke inhalation. Officials said a firefighter was also hurt when he twisted his leg fighting the flames.