One man is dead and his two sons are injured in crash that happened in Carter County. The Tennessee Highway Patrol says the accident happened around 7pm on Gap Creek Road near Tester Road. Sheriff Chris Mathes tells News 5 the truck went off the road and down an embankment, flipping several times. The driver of the truck was not wearing a seatbelt and was thrown from the vehicle. The two boys were wearing their seatbelts and are being treated at the Johnson City Medical Center. No names have been released and the cause of the crash is still under investigation.