It happened around 11:40 Friday night on the 1900 block of Fairview Street.
A resident noticed flames coming from the porch of a home and quickly alerted neighbors. Everyone was able to escape.
More than 100 firefighters were called to the scene to battle the blaze.
Crews were briefly hampered by a ruptured gas line and PECO officials were called to the scene.
No one was injured. The flames caused extensive damage to three homes.
Three families from those homes have been displaced. The Red Cross is assisting.
The cause of the fire is unknown.