The Washington State Department of Transportation (WSDOT) has announced the full closure of the SR 99 tunnel in Seattle after a power outage impacted operations on Wednesday. The shutdown affects both directions, causing significant traffic delays in the downtown area.
Drivers are being urged to seek alternate routes until power is restored and the tunnel can safely reopen. Traffic cameras show vehicles being diverted at the last available exit, with illuminated signs reading “Tunnel Closed — All Vehicles Must Exit.”
WSDOT is coordinating with Seattle City Light and Seattle Department of Transportation as crews work to resolve the issue. No estimated reopening time has been provided yet.
Commuters are advised to monitor traffic updates and allow extra travel time during the closure.
Heads up: Due to a power outage, the SR 99 tunnel in Seattle is CLOSED in both directions.
Seek alternate routes.@SEACityLight @seattledot pic.twitter.com/hJogeo2647
— WSDOT Traffic (@wsdot_traffic) November 20, 2025