Investigators say they’ve found what caused a fire last week that damaged a northwest Iowa business that dates from before the turn of the last century. The fire last Thursday night at Marcus Lumber destroyed two buildings, some lumber, and several of the company’s delivery vehicles. Fire inspectors from the local Marcus fire department and the state say it was apparently accidental. Deputy state fire marshal Dave Schipper says the fire was probably caused by an electrical equipment malfunction in the wiring of a 120-year-old building.