A Knox County farmer has been killed following an accident involving his tractor. The Knox County Sheriff says 81-year-old William Mills was found in a cow pasture by a neighbor, reportedly pinned between a trailer and a gate. WYMT reports Mills had been pulling the trailer with his tractor when he got off the vehicle to open the gate. Officials say although the tractor was in neutral with the parking brake on, the heaviness of the trailer caused it to back into Mills, pinning him between the trailer and the gate.