SEATTLE - Seattle's tunnel boring machine "Bertha" is now less than 100 feet from the finish line, the Washington State Department of Transportation says.

WSDOT tweeted the update Sunday but said the drill's exact breakthrough date is still unclear.

The giant drill started boring a new Highway 99 tunnel beneath Seattle nearly four years ago. When completed, the drill will have traveled nearly two miles, WSDOT says.

The $2.1 billion tunnel to replace the earthquake-damaged Alaskan Way Viaduct was supposed to open in late 2015, but the boring machine broke down and the project hit other snags.

State transportation officials estimate the four-lane tunnel will be completed by late 2018 and would open to traffic in early 2019 after crews connect the tunnel to existing roadways.

The Associated Press contributed to this story.





