A Washington State Patrol Ford F150 was cut in two during a crash Tuesday morning on U.S. Highway 101 south of Discovery Bay. The officer in the patrol vehicle was airlifted to Harborview Medical Center with serious injuries.

Photo courtesy of the Washington State Patrol

A Washington State Patrol commercial vehicle enforcement officer was airlifted to Harborview Medical Center in Seattle with serious injuries after he was struck by a driver while parked on the side of U.S. Highway 101 Tuesday morning.

The Washington State Patrol identified the injured officer as CVEO Alfred L. Alderson, 55, of Port Angeles.

Alderson was inspecting a semi-trailer truck on the shoulder of southbound US 101 after a traffic stop near Milepost 283 south of Discovery Bay at 9:30 a.m. Tuesday. He was sitting in his State Patrol vehicle when he was hit from behind by a white 2005 Ford F350 pickup driven by David S. Johnson, 40, of Sequim, according to the State Patrol.

Earlier reports from the State Patrol indicated that Johnson was suspected of impaired driving, and late Tuesday authorities reported Johnson had been taken into custody for suspicion of vehicle assault.

The 2005 Ford F350 that Johnson was driving had been reported stolen to the Clallam County Sheriff’s Office earlier.

The State Patrol said witnesses reportedly saw Johnson driving erratically south on US 101 before the crash, and said the pickup had been seen passing vehicles in a no-passing zone prior to going off the roadway.

Alderson was sitting in his Ford F150 and had finished his inspection of the semi-truck when Johnson rear-ended his patrol vehicle.

Alderson was not wearing a seat belt at the time of the crash, according to the State Patrol, as he was just about to get out of his truck.  

The impact of the Ford F350 pushed the patrol truck into the semi and the impact cut the truck in two.

The highway was closed for hours after the crash, and was later reopened to one lane of traffic.

Johnson was also airlifted to Harborview Medical Center.

The State Patrol said Alderson has been a WSP employee since September 2011, and works primarily in Jefferson and Clallam counties.