RICHMOND ? No foul play was involved in a car fire that killed a Garnett woman Wednesday, the Franklin County sheriff said.

Sheriff Craig Davis said in a news release that Lena Roye Mathenthin, 39, was apparently driving home when her vehicle became stuck in a ditch two miles west of Richmond.

As Mathenthin attempted to drive out of the ditch, the catalytic converter or muffler system set fire to dry grass under the car. The fire spread to the car’s passenger compartment.

Davis said it was unknown why Mathenthin didn’t escape the vehicle.

Deputies and firefighters arrived at the scene of the grass fire Wednesday to find the burned-out car wreckage.

Davis labeled the incident as suspicious after the woman’s body was found inside the car at 11:50 p.m.

The Kansas State Fire Marshall’s Office and the Kansas Bureau of Investigation assisted with the investigation.