A man who was lying in the road was killed on eastbound Interstate 90 just west of the Snoqualmie Pass summit.
He was hit and killed by a car shortly before 11 p.m. Sunday, according to the Washington State Patrol.
The victim is a 23-year-old Lynnwood man.
The Washington State Department of Transportation posted that all the eastbound lanes were closed at 12:07 a.m. Monday while state troopers investigated.
The lanes reopened shortly before 4 a.m.