8:23 AM: If you drive, bicycle, or use transit on 4th Avenue South south of the West Seattle Bridge (Spokane Street Viaduct), plan an alternate route – a crash at 4th/Industrial (near Costco) is reported to be blocking both directions of 4th in the area, including the bridge over the railroad tracks. Buses are being diverted. The image above is from the SDOT camera at 4th and Michigan, south of the crash scene and north of the 1st Avenue South Bridge.

9:36 AM UPDATE: Seattle Fire says their crews spent 15 minutes cutting the driver out of the wreckage. He is 55 years old and in critical condition with head trauma, according to SFD.

11:11 AM UPDATE: SDOT has tweeted that the scene is clear.