The incident occurred around 8:15 p.m. on Thursday, on the 3400 block of Haverford Avenue.
Crews arrived on the scene to find flames on the second floor.
The building is right next door to the Engine 44 fire station, and crews were quickly able to get the fire under control.
Four men were taken to the hospital with injuries. There's no word on their conditions.
The cause of the fire remains under investigation.