A Mitsubishi Lancer that was parked on the right shoulder was hit from behind by a 2006 Subaru Forester, state patrol said.
Troopers shut down the right and center lanes of I-5 north for about three hours early Thursday to investigate the crash.
A Vancouver man was arrested on suspicion of vehicular assault after crashing into a parked car on Interstate 5 late Wednesday, officials said.
The crash happened just before midnight on Interstate 5 north between the City Center and East Mill Plain Boulevard exits, said Trooper Ryan Tanner, a state patrol spokesman.
A 2006 Subaru Forester driven by Preston D. Garrison, 41, of Vancouver was heading north on I-5, veered to the right shoulder and hit the rear of a parked 2005 Mitsubishi Lancer, a state patrol bulletin said. It was not known why the Lancer was on the freeway shoulder.
Two engines and one truck from the Vancouver Fire Department responded to the crash, said Capt. Dave James, a fire department spokesman.
Firefighters found a man trapped in the Lancer with life-threatening injuries, James said. The driver of the other car was out of the car and appeared to have serious injuries, he said.
Samuel R. Brackeen, the 27-year-old Vancouver man who was in the parked car, was sent to PeaceHealth Southwest Medical Center with a head injury, internal injuries and fractured ribs, the state patrol said.
Brackeen was listed in critical condition Thursday afternoon, said Ken Cole, hospital spokesman.
Garrison was sent to PeaceHealth Southwest Medical Center with cuts on his forehead and rib injuries.
Alcohol was a “big factor” in this collision, Trooper Tanner said.
Garrison was arrested after being released from the hospital on suspicion of vehicular assault.
The right and center lanes of I-5 were blocked for about three hours while troopers investigated, Tanner said.
The investigation is ongoing.