What happens if Bertha breaks down under the viaduct?

In the Alaskan Way Viaduct shutdown, many questions have been tweeted and shared on Facebook.
The biggest: What happens if Bertha malfunctions underneath the viaduct?

Tunnel-boring machine Bertha is notorious for being behind schedule – in part due to breaking down and repairs.

Washington State Department of Transportation closed the viaduct on Friday morning so that Bertha could tunnel.

After the 2001 Nisqually earthquake, issues were exposed with the viaduct and transportation leaders decided it needed to come down.

In place would be a replacement tunnel.

KIRO 7 News asked WSDOT what it would mean for the viaduct if Bertha broke down beneath it.

"The contractor is responsible for the machine, and we'll have to make any kind of repairs that happen," WSDOT Alaskan Way Viaduct deputy program administrator Dave Sowers said. "Obviously the machine has gone through an extensive amount of repair after it broke down. In light of that, the machine is better … and is ready for the journey."

The Viaduct is estimated to reopen in roughly two weeks, but It could take longer. Final word on reopening will depend on when the viaduct is deemed safe for driving.

Sowers said that driving under the viaduct is safe because theconcern relates to the proximity of the machine to the foundations that support the viaduct.

As Bertha is tunneling under ground, she will be 80 feet below the ground surface -- but just 15 feet below the foundations.

Crews are protecting the viaduct with carbon fiber. KIRO 7 News morning anchor John Knicely explained in a video how that works.

Engineers say they will be watching Bertha “like a hawk” in the upcoming weeks.

For real-time updates on the viaduct shutdown, click here.

Cox Media Group