Sioux Falls Argus Leader: Deere & Co. is denying that a design flaw led to catastrophic fires in one of its models. In its response to a lawsuit brought by three South Dakota farmers, Moline, Ill.-based Deere says the John Deere 9620RX tractor “conformed to the state-of-the-art at the time it was designed, manufactured, packaged, and labeled.” The lawsuit says the plaintiffs bought the tractor in December 2015 for $462,229 and it was destroyed when it caught on fire while being operated in October 2017. The suit contends the tractor was defective because a design flaw failed to shield debris from accumulating around the exhaust system.