It happened around 3 a.m. Tuesday at a two-story rowhome on the 5600 block of Spruce Street in West Philadelphia.
Crews arrived to heavy smoke in the home.
Just around 3:15 a.m., a firefighter fell 20 feet and suffered a head injury. The firefighter was taken to Penn Presbyterian Medical Center and is listed as stable.
Officials have not said if there was anyone in the home at the time of the fire.
A cause is under investigation.