Two construction workers from the Tri Cities have been killed while working on a guardrail along Interstate 75 north of Knoxville. A truck, pulling a 20-foot flatbed trailer, veered off the highway in Anderson County yesterday morning, striking 18 year old Cheyenne Dakota Burke of Bulls Gap and 19 year old Jeffrey Brian Thompson II of Rogersville. Officials say they were tightening a cable on a traffic barrier when they were struck by a truck being driven by James Hatfield of Huntsville. He was treated for minor injuries. The deaths are being investigated as a vehicular homicide, but troopers are looking into the possibility the driver suffered from a medical condition.