Officials: Explosion, Fire, Explosion In Home Not Accidental

TEMPE, Ariz. (AP) — An explosion and fire in a Tempe house where two women were found dead wasn't accidental, but circumstances of the incident remain unclear, city officials announced Friday.

Investigators determined that the explosion occurred early Monday morning when vapors from unknown accelerants came into contact with “an ignition source," a city statement said.

The investigation is in its early stages but investigators ruled out natural gas as causing the explosion and “can confirm that the cause of fire was not accidental," the statement said. "This can be confirmed as an isolated incident."

The statement did not identify the ignition source and said items from the scene were sent to a lab for testing.

A mother and her adult daughter lived in the home but officials said the Maricopa County Medical Examiner's Office hadn't yet confirmed their identities.

Causes of death also remain pending.

Surveillance video didn't show anybody else at the home so there was no immediate indication of involvement by another person and there was no indication of a possible motive, officials said during a news conference.

“What we can answer right now is that it was not accidental," said Assistant Fire Marshal David Fabok.

Fire crews arriving at the fire at about 1:30 a.m. found the one-story home fully engulfed.