As a team of 10 investigators searched Wednesday through the sooty aftermath of a house fire that killed an infant girl in Upper Southampton, neighbors remininsced about the generosity of her family.

Margaret Binsfeld recalled the day that the girl's mother, Susan Thomas, who with was injured along with an older daughter in the Tuesday fire, had given her a load of toys.

Binsfeld remarked to Thomas that she wished she had more playthings for her visiting grandson.

"She went back home, and the next thing I know, she's ringing the bell with a basketful of toys," said Binsfeld, 60, a nurse at the Hospital of the University of Pennsylvania. "She told me I could keep them."

Thomas, 33, was being treated at Temple University Hospital for smoke inhalation, Upper Southampton Police Chief Ron MacPherson said.

Her 17-month-old daughter, Kate, died in the fire. Another daughter, Julia, 4, was being treated for smoke inhalation at Children's Hospital of Philadelphia, MacPherson said.

Julia's condition improved Wednesday, he said, but Thomas' prognosis had not been determined.

Investigators did not yet know the cause the fire, Township Fire Marshal Mark Shoemaker said. Foul play had not been ruled out, but authorities had not found anything that would support that finding, MacPherson said.

The fire started in the living room of the two-story home on Carolyn Drive, which Thomas shared with husband, Eric Nordberg, and their children.

Authorities arrived shortly after 2:13 p.m. Firefighters tried to rescue the family by entering the back of the house, Shoemaker said. They heard smoke alarms.

But the smoke was so intense in the back that firefighters went to the front of the house. Thomas and her children were found unconscious in an upstairs bedroom. The family dog, Seymour, a golden retriever, was found in another bedroom and did not survive.

The family was taken to St. Mary Medical Center in Middletown Township. Kate died there of smoke and soot inhalation, and Thomas and Julia were transferred to the other hospitals.

Another daughter, Bethany Nordberg, 14, was on her way home from school when she learned of the fire.

Neighbors recalled that Nordberg, who runs a Center City courier company, was often seen biking around the neighborhood in biker shorts and his helmet. He sometimes biked to work.

Thomas and her children often walked Seymour around the neighborhood. The family had planned a barbecue Sunday, and Binsfeld and her husband, Dennis, were invited with other neighbors.

"It's so sad," said Dennis Binsfeld, 68, who described the Thomas-Nordbergs as a do-anything-for-you kind of family. "They are such nice people."

Contact staff writer Kristin E. Holmes at 610-313-8211 or kholmes@phillynews.com.