GRUNDY COUNTY, Mo. — A Mercer man was injured in a Grundy County motorcycle accident Saturday afternoon. A Missouri State Highway Patrol report states  Sean M. Graham, 20, of Mercer, was driving a Chevrolet Silverado northbound on U.S. 65, just north of Trenton, at 4:05 p.m. A mattress blew out of the bed of his truck and into the path of a Harley Davidson, driven by Jacob I. Graham, 20, also of Mercer. Graham’s motorcycle hit the mattress and went off the east side of the roadway, ejecting him. Graham was transported by Grundy County Ambulance Service to Wright Memorial Hospital for treatment of moderate injuries.