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Big Bertha Takes A Break

caption: Digging for the Highway 99 tunnel has been halted since Bertha, the digging machine, hit an unknown impediment on Friday. Pictured here is the wake of the giant machine as it burrows under Seattle.
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Digging for the Highway 99 tunnel has been halted since Bertha, the digging machine, hit an unknown impediment on Friday. Pictured here is the wake of the giant machine as it burrows under Seattle.
Flickr Photo/WSDOT

The giant tunnel boring machine that’s chewing its way under downtown Seattle is stopped in its tracks and officials are trying to figure out why.

Washington Transportation Department spokeswoman KaDeena Yerkan said the machine, nicknamed Bertha, hit some kind of obstruction Friday night.

Late yesterday, managers were still trying to figure out what that might be. Yerkan said they don't know whether the obstruction is man-made or natural.

Bertha is tunneling 60 feet below the surface, between South Jackson Street and South Main Street. It's digging a tunnel to replace the Alaskan Way Viaduct to carry Highway 99 traffic.

The department said the machine has traveled about 1,000 feet along its two-mile route since tunneling started last summer.

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