Authorities say a Sebastian County sheriff's corporal was critically injured when his patrol car crashed in Lavaca.

Sheriff's Investigator Philip Pevehouse says Cpl. Terry Johnson was injured in the crash on state Highway 96 about 4:20 a.m. Saturday. Pevehouse says Johnson was on routine patrol at the time and that the cause of the crash is still under investigation.

Pevehouse says the collision was reported by a resident who said he heard a loud crash then saw the patrol car on its side and off the roadway.