A South Jordan youth died Saturday after an accident on a recreational vehicle in Sevier County during a family outing.

Richard "Ricky" Walter Thornton, 13, died instantly from head injuries sustained when he lost control of the all-terrain vehicle he was driving. A passenger riding on the vehicle, Jacob Freeborn, 11, wasn't injured in the accident. Neither boy was wearing a helmet.The accident occurred in Sevier County's Grass Valley, two miles northeast of the Koosharem Reservoir on the Kings Meadow Ranch Road in Sevier County. Deputy sheriffs Charles Ogden and Norm Cole responded to the accident scene.