State troopers responded to the scene, at the intersection of Highway 9 and 2nd Street in Snohomish, at about 4:40 a.m. after receiving a report of an accident involving a semi.
A preliminary investigation found that the semi truck was turning onto Highway 9 when the load shifted and stacks of lumber spilled onto the highway, the State Patrol said.
A box truck traveling south managed to stop before hitting the lumber, but a car heading north was unable to stop in time. It hit the lumber, then the box truck.
The driver of the car, a 64-year-old Arlington woman, sustained minor injuries and was taken to Providence Regional Medical Center in Everett. The driver of the box truck was unhurt.
A Dodge pickup also crashed into the pile of lumber, sustaining about $5,000 in damage.
The driver of the semi truck, a 48-year-old Marysville man, faces a possible charge of failing to secure his load.
The intersection was blocked by the accident for about three hours, reopening at about 7:50 a.m.