PHILADELPHIA — Fire raced through a row of two-story homes in southwest Philadelphia early Saturday, killing 4-year-old twin girls, a 4-year-old boy and a baby and engulfing at least 10 houses, officials said. A mother and three of her children escaped through a second-floor window.

The blaze began shortly before 3 a.m. and was brought under control in about an hour, fire officials said. At least eight row homes were gutted, leaving behind only charred frames. The cause of the fire remains under investigation, but witnesses said it may have begun on a couch on a porch.

The twins’ mother, 41-year-old Dewen Bowah, told police she was in the home with seven children and managed to get three of her other daughters out before jumping from second-floor window. But she couldn’t save the twins, Maria and Marialla Bowah, or 1-month-old Taj Jacque and 4-year-old Patrick Sanyeah. The boys’ mother wasn’t in the home at the time.