PORTLAND, Ore. -- A two-vehicle crash Sunday night on Interstate 5 near Hayden Island killed one person and sent three to the hospital, including a police officer assisting with the crash.

Two officers were sitting in their patrol car on southbound Interstate 5 with the emergency lights on when the driver of a Ford Focus crashed into the patrol vehicle.

One of the officers was taken by ambulance to a hospital with serious but non-life-threatening injuries. The other officer was treated at the scene.

Officers arrived at the crash on northbound Interstate 5, north of Marine Drive and south of the Interstate Bridge, at 6:43 p.m. They found a white Ford Mustang and Chevrolet pickup truck, both occupied by two people, had crashed.

One occupant of the Ford Mustang was declared dead at the scene, and the other was suffering from what were believed to be serious, life-threatening injuries.

One of the occupants of the Chevrolet pickup truck was taken by ambulance to the hospital for what was believed to be a non-life-threatening injury. The second occupant of the Chevrolet pickup truck did not require medical transport.

Speed is believed to have been a factor in the crash.

The crash shut down all three lanes of northbound I-5 for several hours.