Correction 8/1/13: A previous version of this story stated that the tunnel contractor had drilled through a power line but missed hitting live wires. In fact, the tunnel contractor drilled through a concrete power vault and it missed hitting the power lines inside.
The world’s largest tunneling machine started grinding into the soil beneath downtown Seattle Tuesday afternoon. The machine known as Bertha is digging a 58-foot-wide tunnel to replace the Alaskan Way Viaduct.
Bertha is here. The world’s largest tunnel boring machine arrived in Seattle Tuesday after being shipped from Japan. It’s expected to reach land sometime this week. After that, in a few months, it will get to work drilling the tunnel that will replace the Alaskan Way Viaduct.