A call came in to authorities at 5:39 p.m. for fire crews to check on an alarm system at 1720 Sansom Street.
Shortly after arrival, it was determined that the fire was actually coming from a property that faced Moravian Street.
Crews made entry where they discovered the heavy fire in the rear.
At 5:49 p.m. a supervisor on the scene called for additional equipment.
Fire crews had some difficulty due to the way the building was constructed.
The fire was placed under control shortly after 6:00 p.m.
One firefighter suffered minor injuries and was taken to Hahnemann Hospital for treatment.
There is no word on a cause for the fire.
Four people have been displaced. They were able to find shelter with relatives.
