A semi truck hauling hay was southbound on Interstate 29 in the area of mile marker 146 when, for unknown reasons, the hay started on fire. The semi came to a stop on the shoulder of the southbound lane and the driver was able to get out of the semi without injury. Both lanes of southbound traffic were closed down to traffic while Manvel and Thompson Fire Departments extinguished the fire. Grand Forks County Sheriff's Deputies were on scene and assisted with traffic control. Altru Ambulance personnel were also on scene to assist.The incident caused interstate 29 to be closed for 3 hours, while DOT crews cleared the debris from the roadway.