8 Massive Tunnels Being Built Right Now Under A City Near You

Now that we know it was an eight-inch steel pipe that brought the world's largest-diameter tunneling machine to a halt up in Seattle, we can no longer fantasize about Bertha unearthing a five-story-tall buried locomotive. But we can look at something almost as fascinating: The other giant holes that are currently… »1/07/14 9:20am1/07/14 9:20am