Investigators have identified two potential causes of the deadly fire at a Fall River assisted living facility, but since they can’t pinpoint the exact origin, it’s officially been ruled “undetermined.”

Bristol County District Attorney Thomas Quinn III and State Fire Marshal Jon Davine held a news conference Tuesday afternoon to release their preliminary findings.

Davine said the fire at Gabriel House began in a resident’s room on the second floor where investigators found an oxygen concentrator and “numerous smoking materials.”

The two possible causes, according to Davine, were a malfunction of the oxygen machine or the improper use or disposal of smoking materials. Regardless of what caused it, Davine said the fire was “clearly accidental.”

See more at wpri.com.