A serious crash on Seattle's Alaskan Way Viaduct involved over a dozen vehicles and injured multiple people Sunday afternoon.
Witnesses say the incident began when a driver of a box truck started losing control and crashing into vehicles while driving north on the viaduct.
The truck went down an off-ramp at Western Avenue and Bell and struck moving and parked vehicles along the way. Police say the driver rear-ended a car and crashed into a support column for the viaduct.
Seattle firefighters say at least six cars were totaled and at least four people were injured, including the truck driver.
Witnesses believe the driver of the box truck suffered a medical emergency; the driver was transported to Harborview Medical Center in serious condition.
Two other people were transported by ambulance to area hospitals in stable condition, and one person was able to leave the scene on their own.
The Washington State Department of Transportation inspected the structural integrity of the support column.
