A 14-month-old girl died in an early-morning rowhouse fire yesterday, apparently forgotten by her father and two brothers, who rushed past her through the thick smoke as she slept on the sofa.

"We believe it was in the panic of everybody exiting the building that the baby was left behind," City Fire Commissioner Lloyd Ayers said.

Not until the flames were extinguished at 12:20 a.m. - 20 minutes after the blaze started in the 4900 block of West Thompson Street in the city's Parkside section - did firefighters find the body of Jessica Smith. Her two brothers, ages 3 and 5, had been playing with matches and accidentally set the bed on fire, authorities said.

The boys alerted their father, Emmanuel Peters, who got them out in time and then forgot to tell firefighters about the baby, authorities said. Peters, who was not injured, drove the boys to Children's Hospital of Philadelphia, where they were treated for smoke inhalation.

Meanwhile, the children's mother, who was at a store getting something to eat when the fire broke out, returned and saw the flames, Ayers said. She begged to be allowed to go inside to get the baby, but firefighters stopped her.

It was too late.

"It's always a sad thing when any life is lost in a fire, particularly in the case of an infant whose life is just starting," Fire Chief Daniel A. Williams said. This was the 25th fire fatality this year, he said.

The house had smoke detectors, but they had no batteries or dead batteries, the chief said. The Fire Department urges people to use smoke alarms and to practice a planned escape in the event of fire.

The home, whose upper two floors were unoccupied, is heavily damaged and uninhabitable, the chief said.