Firefighters were called to the 4200 block of Parkside Avenue around 6:30 a.m.
A resident said she smelled smoke and then pulled the fire alarm to warn the four families who live in the building.
"I looked up at the sky and I saw smoke coming out," said Inayah Hart. "I ran and pulled the fire alarm and ran back in and tried to grab important papers, but it filled up with smoke so fast so I just ran out."
Heavy flames could be seen shooting from the roof of the three-story apartment-house in the middle of the block. Black smoke billowed out of the home as the fire quickly spread to an adjoining home.
"My son came and got me he said there are flames on that roof I could feel coming to my house," said neighbor Rachel Taylor.
Fire crews were able to get the fire under control in about an hour, while also battling the heat and humidity
"The rooftop on top of the roof posed a challenge for us that we were able to overcome," said Philadelphia Fire Department Deputy Chief Anthony Hudgins.
Crews said 11 residents were evacuated.and there were no injuries thanks to working smoke alarms
The fire was placed under control around 7:30 a.m. but crews remained on the scene battling hot spots.
There are no reported injuries at this time.
Multiple residents told Action News they heard and saw fireworks coming from this area last night.
Investigators said they are looking into if fireworks caused the fire, but there is no official word yet on what sparked the blaze
***This story is developing. Check back with 6abc.com for updates.***