SPOKANE VALLEY, Wash. -- Crews responded to a large commercial structure fire at Best Bet Auto in Spokane Valley just before 4:30 a.m. Wednesday morning.

The first arriving crews assessed the fire conditions and deemed the structure was unsafe to enter for an offensive fire attack. Crews decided to set up hoses, aerial master streams and dump water on the fire from outside of the structure. Exposure protection lines were put in place to the west of the structure to protect another building from the spread of fire.

Sprague Avenue was closed for two hours as a result of the fire.

Law enforcement said they do not believe anyone was inside the building at the time the fire started. The Fire Chief confirmed the building was vacant and that all electricity and gas in the building were turned off.

Fire crews said they are investigating the cause of the fire. As of Wednesday afternoon, investigators said the official cause is "undetermined," though investigators were not able to rule out a warming fire generated by transients or an intentionally caused fire.

Officials said the structure was completely destroyed and valued at $85,000. No one was hurt.