'De-watering wells' next at stalled Seattle tunnel

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SEATTLE — The Transportation Department says crews are drilling "de-watering" wells Thursday to relieve pressure on a machine that has become stuck while boring a highway tunnel under downtown Seattle.

Spokeswoman KaDeena Yerkan says the wells should make it easier to identify what's blocking the machine known as Bertha. Then contractors will determine how to proceed.

The machine was halted Saturday by the mysterious obstruction. It may be a huge boulder.

The boring machine is 60 feet under the streets and about one-tenth of the way into the planned 1.7-mile tunnel that will carry Highway 99 traffic and replace the Alaskan Way Viaduct.