Contractor says highway tunnel under Seattle to open in August 2017, 20 months behind schedule

Transportation officials say a new highway tunnel through downtown Seattle won't be open until August 2017, more than 20 months behind schedule.

The Washington Department of Transportation said Monday that the contractor, Seattle Tunnel Partners, expects to resume tunneling in April.

The contractor and state officials say they can't nail down an exact completion date until repairs are made to a tunnel-boring machine that's stuck underground and tunneling resumes.

The $2 billion tunnel is designed to replace the aging Alaskan Way Viaduct after it was damaged in a 2001 earthquake.

The massive tunnel-boring machine stopped work on the 2-mile tunnel in December 2013 after going about 1,000 feet, and repairs are needed before drilling can resume.