A fire Monday night at an east Lawrence vehicle detailing shop was an accident because of an improperly installed flue duct system for a heated power washer, a Lawrence-Douglas County Fire Medical spokeswoman said Thursday.

Division Chief Eve Tolefree said damage was estimated to be $8,000 to Richard’s Detailing and Mobile, 827 Garfield St.

Shop owner Richard Steward earlier this week said fire damaged the east wall of the business and two cars in the shop sustained smoke damage. He said earlier that fire investigators told him a spark must have ignited the fire from an insulated pipe that leads to a pressure washer the business uses.