A house fire that killed a mother and daughter has been ruled accidental, fire officials in Fairfax County announced Thursday.

Investigators said they traced the blaze, which ripped through a single-story home on Manor Road in Falls Church early in the morning on Jan. 23, to a wall-mounted natural gas heater in the living room.

The exact point of failure could not be determined, officials said.

The fire claimed the lives of 48-year-old Laura Snyder-Gardner, a math professor at Gallaudet University, and her 16-year-old daughter, Mary Ann, who was a student at the Model Secondary School for the Deaf.

According to the medical examiner, the cause of death was smoke inhalation. Officials said there were smoke alarms in the home, but they could not determine if they were visual alarms because of the extensive fire damage.

Laura Snyder Gardner, is believed to be one of the victims in a fatal house fire in Falls Church Tuesday. (Photo courtesy of Rocco Leo Gaglioti) (Courtesy of Rocco Leo Gaglioti/COURTESY OF ROCCO LEO GAGLIOTI)

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