Large-scale disaster drill to take place inside State Route 99 Tunnel Thursday

SEATTLE — If you’re near the northbound side of the State Route 99 Tunnel on Thursday, you may see Seattle fire and police departments hard at work.

Response crews will practice what to do if an accident happens inside the tunnel with cars and drivers trapped inside.

The Washington State Department of Transportation says it spent a year and a half planning this exercise. Their goal: to learn as much as they can from it so that all agencies can be prepared for an emergency inside the tunnel.

After announcing the tunnel will open in early 2019, WSDOT says multiple agencies are ready to respond to a large-scale, simulated accident inside the SR 99 Tunnel Thursday.

“Right now, there are 12 vehicles altogether that we’re pre-staging, eight cars and three buses. We’ll have upwards of 24 people that are injured. Captain Sano mentioned the moulage. They’ll actually have simulated makeup on to demonstrate those injuries and make it as realistic as possible,” said Brittany Miller, WSDOT deputy emergency manager.

WSDOT, Seattle fire and police and the transportation departments will practice working together as the tunnel’s fire suppression system is also activated.

“Traffic Management Center in Shoreline is going to be staffed 24-7. They’re keeping an eye on the tunnel. They’re able to assess quickly what would be the best way approach for the Fire Department to make access into the tunnel,” said Dave O’Brien, battalion chief with the Seattle Fire Department.

Signage will tell drivers to either exit the tunnel on foot or remain in their cars. Traffic officers will also be dispatched to the scene.

Administrators say the drill allows first responders to familiarize themselves with the tunnel and all of its safety features.

“Once the tunnel is open, we don’t just stop and ignore everything. We continue to work with fire and police, continue to develop plans and change plans,” said Morgan Balogh, with WSDOT regional traffic operations.

WSDOT also said the SR 99 Tunnel will have a 17-person maintenance crew checking its operating systems four days a week.