STURGIS, S.D. – Fire investigators say the cause of a fire that heavily damaged Weimer’s Diner and Donuts in Sturgis last month was accidental.

Tony Managan, a spokesperson for the State Fire Marshal’s Office, said the origin of the fire was located in an old extension cord that led to a freezer at the restaurant.

Sturgis Volunteer Fire Department Chief Scott Lensegrav and a state fire marshal investigated the scene of the fire just after it happened on Wednesday, Aug. 19. Lensegrav said that officials with Weimer’s insurance company also had visited the site.

It is not known if the business owners plan to reopen.