Overturned semi closes express lanes on I-5 South near downtown Seattle

Express lanes remain closed on I-5 South near Mercer Street in Seattle while crews work to clear an overturned semi. 

The semi drove off the road, and his trailer fell off the side of the highway. 

The driver was taken to Harborview Medical Center but troopers say they don't know the extent of his injuries.

WSP says there's no ETA on when the lanes may reopen. 

Photo courtesy WSP