PARKERSBURG, W.Va. -- Fire officials believe a fire that killed two young Parkersburg girls began in a dining room on the first floor of the family's duplex.

Fire Chief Eric Taylor tells the Parkersburg News and Sentinel that investigators don't know whether a gas-fired wall heater in the dining room was the fire's source.

The fire occurred Saturday.

The bodies of the girls, ages 2 and 4, were sent to the state medical examiner's office in Charleston. A spokesman for the office says they haven't been positively identified.

A 3-year-old boy and an adult male who were in the duplex were treated at a hospital for smoke inhalation.