The explosion happened inside 32-25 Leavitt Street just before 8 p.m. All the occupants have been accounted for.
Two residents were pulled out of the building by firefighters. One victim was found on the basement floor, a man who'd suffered serious burns. A woman was also trapped on the first floor of one of the damaged homes. Neither injury appears life threatening.
According to reports, the back of the home is blown out and the front is bowed out. The back of the building suffered the most damage.
The fire department says the explosion occurred on the first floor, where a resident was working with a propane tank when it suddenly exploded.
About 110 firefighters and 25 units responded to the fire.