The SR 99 tunneling machine, Bertha, breaks through to daylight on April 4, 2017 near Seattle’s iconic Space Needle after tunneling 1.7 miles underneath downtown Seattle. See what one of the world’s largest tunneling machines looks like up close as only a drone can show.
–wsdot on YouTube
Tags: Bertha, Seattle, SR 99, SR 99 Tunneling Machine, Video, WA, Washington, Washington State Department of Transportation, WSDOT, YouTube