Witnesses said two cars sped by them going about 90 mph on southbound State Route 509 just before the crash, which happened shortly after midnight near the Cloverdale intersection.
Washington State Patrol Trooper Karim Boukabou said the 21-year-old driver of a Nissan 350 lost control of the car and rolled over onto its roof. The driver had to be extricated and was taken to Harborview with unknown injuries. His condition was unknown at 5 a.m.
The 22-year-old driver of the other car was arrested for vehicular assault following the crash. The driver told reporters he and his friend had just left work for the evening and may have been driving too fast, but were not racing.
SR 509 was closed for a five hours after the crash, but reopened around 5 a.m.
Washington State Patrol troopers are investigating the crash.