Police and medics responded to the scene, at Highway 99 and 220th Street SW, at about 6:15 a.m. after receiving a report of a serious crash.
Leslie Hynes of Snohomish County Fire says two cars collided at the intersection and one of them veered off the highway and into the side of a former auto parts store that has been remodeled.
Two patients with minor injuries were taken to Swedish Edmonds Hospital.
The building has minor structural damage.
Some lanes are blocked at the accident scene, but traffic is getting by without much disruption.