A 20-year-old South Philadelphia woman carried water from bathroom to bedroom in fruitless attempts to extinguish a mattress fire before she was overcome by smoke yesterday morning, fire officials said.

The water was still running when firefighters found her. The woman, whose name was not released, was taken to Thomas Jefferson University Hospital, where she died.

Her mother and grandmother escaped unharmed.

Fire officials responding to a 5:35 a.m. call in the 1200 block of Latona Street said a second-floor back bedroom was in flames when they arrived. They found the victim toward the front of the end-unit rowhouse, where the fire was contained.

The cause of the blaze was careless use of an open flame, fire officials said. The house had no working smoke alarms.

Executive Fire Chief Daniel Williams said people should not try to fight fires.

"Get out and stay out," he said.

Contact staff writer Mari A. Schaefer at 610-892-9149 or mschaefer@phillynews.com.