WYOMING — An observant, quick-thinking passerby saw a Wyoming Highway Patrol car involved in a crash and stopped to help. The effort may have saved a trooper’s life.

A WHP trooper was finishing up with a previous crash, stopped on the shoulder of US 212 just west of Colony, Wyoming Monday when the cruiser was struck from behind.

An eastbound commercial vehicle jackknifed, causing the trailer to strike the back of the stopped Highway Patrol vehicle. The trooper, who was in the driver’s seat, was knocked unconscious.

A passing motorist witnessed the crash and was first on the scene. Seeing the trooper out cold, the passerby used the trooper’s radio to call for assistance.

The WHP trooper was transported to Monument Health in Spearfish, South Dakota for injuries sustained in the crash. The trooper who was injured also is assigned a K-9. His K-9 partner was inside the vehicle when he was struck, but was not injured.

The driver of the commercial vehicle was also not injured in the crash.