PHILADELPHIA (AP) - Authorities say a fire in a north Philadelphia row house claimed the life of a teenage boy.

Fire officials said the blaze broke out just after 5 p.m. Monday on the first floor of the Olney home.

Commissioner Lloyd Ayers told The Philadelphia Inquirer that the 14-year-old autistic youth was being escorted out by his adult sister but became afraid and bolted back upstairs.

Ayers said the woman couldn't follow the boy and instead helped two younger children escape.

Capt. Clifford Gilliam said fire crews arrived in minutes but found flames roaring out of the first floor.

The boy was found in a second-floor bedroom and taken to Einstein Medical Center, where he was pronounced dead about two hours later.

The cause of the fire remains under investigation.