The blaze broke out around 6:40 p.m. at a home on the 200 block of Walnut Street.
Officials say a Darby firefighter was shocked by an electrical wire, but will be okay.
He was transported to the Hospital of the University of Pennsylvania as a precaution.
Another firefighter was treated for smoke inhalation at the scene.
Action News spoke with a neighbor, whose home was also affected by the fire.
He and his dog were able to make it out unharmed. His wife and children were out at the time.
The neighbor says the family in the rowhouse where the fire began was not at home.
The fire was placed under control by 8:00 p.m.
The Red Cross is helping those displaced by the fire.