Yusef Perry was walking home from work around 11:30 p.m. Saturday when he saw flames shooting from the porch of his West Philadelphia rowhouse in the 5800 block of Cedar Avenue. He knew his great-grandmother was inside, alone, sleeping in the living room.

"I started banging on the window real hard to get her up. There just wasn't time to get my key out," said Perry, 18, who'd finished a shift at Staples.

Startled, Elaine McMullen, 76, awoke. She said that at first she couldn't figure out why Perry was doing "all that hollering." Then she looked out the window.

McMullen is one of two dozen mostly elderly occupants who escaped the inferno that damaged 12 rowhouses and displaced several families. Four of the two-story rowhouses were destroyed and condemned; eight are still habitable, according to officers with the city department of Licenses and Inspections.

Fire officials said the blaze was under investigation. Only one person had to be rescued from her burning home, and she was transported to Mercy Hospital of Philadelphia.

The woman, Ruth Dennison, 76, an invalid, was fine yesterday after being treated for respiratory problems and released, according to her brother, Jacob Dennison.

Fire Marshal John Dougherty said the three-alarm fire was brought under control in 80 minutes. He said the fire started in belongings on the porch of the rowhouse at 5815 Cedar Ave. The fire then quickly spread to the other dwellings.

Neighbors said the occupants of that rowhouse had moved out a few days earlier and some of their items were still on the porch. The renters were new to the neighborhood, according to several residents who said they had lived on the block most of their lives.

Neighbors gazed at the charred rowhouses in shock yesterday and recalled how the flames had melted parked cars and jumped to electrical wires, causing loud pops. The most heavily damaged homes, in the middle of the block, were ashen and the upstairs bow windows had shattered in the intense heat. Outside, a tree was reduced to a blackened silhouette.

The Southeastern Pennsylvania Chapter of the Red Cross is providing housing for two displaced families at its Red Cross House at 40th Street and Powelton Avenue. Financial assistance was given to five other families who were able to move back into their homes yesterday afternoon, spokeswoman Jennifer Lee said. She said three other families found temporary housing with relatives or friends while their homes are repaired.

Nicole McRay, 35, who has lived there all her life, said she was trying to look on the bright side.

"I'm just glad we're alive. Material stuff can be replaced," she said.

Like many others, she was sleeping when the fire broke out. Her father got her up and they fled through the back door into the alley.

Felicia Brown, 31, also had gone to bed after tucking in her three children, ages 5, 8 and 10. But she said she stirred when she smelled "something funny." Soon she felt the heat coming off the walls and saw the flames.

"I grabbed the baby and then the other two and said, 'Let's go,' " she said. "But the fire was in front of us and we went out the back door. We're fine - just shook up."

Contact staff writer Jan Hefler at 856-779-3224 or jhefler@phillynews.com

Inquirer staff writer Harold Brubaker contributed to this article.