The Chester Fire Department and Pennsylvania State Police are investigating the Chester fire that killed a 4-year-boy Friday night.

The blaze started in the first-floor living room in the front of a house in the 1100 block of Terrill Street, Jack Powers, battalion chief of the Fire Department, said Saturday.

The victim was in a second-floor bedroom and apparently died from the smoke, Powers said. An autopsy is scheduled for Sunday, a spokesman for the Delaware County Medical Examiner's Office said.

Authorities declined to identify the victim, pending notification of all relatives.

Though the cause of the fire remained under investigation, it did not appear to have been deliberately set, Powers said.

The two-alarm fire broke out about 8 p.m. Friday and was under control about 45 minutes later. It gutted the house.

An 18-year-old babysitter in the house was taken to Crozer-Chester Medical Center with injuries. She was in stable condition Saturday, a spokeswoman at the burn unit said.