Dawn Burns Percival, 72, of Bryan was killed Tuesday afternoon in an accident on Highway 21 south of Grist Mill Road. The accident involved an 18-wheeler and a passenger vehicle. Percival, the driver of the Cadillac CTS, was killed at the scene. The driver of the 18-wheeler, a 57-year-old man from Wylie, was also injured in the accident. He sustained cuts and bruises. The Texas Department of Public Safety reported that Percival’s car left the road and overcorrected into the northbound lanes and was struck by the 18-wheeler. The car then caught fire.