In this image taken at the Metro Bus Tunnel portal between Jackson Street and Main Street near Fourth Avenue, workers from Shaughnessy Moving Engineers and Atkinson and Dillingham Construction Company remove the last of two iron support beams that held up the huge new Robbins boring machine, nicknamed the "Mole," during transportation. At its starting place in this photo, the machine was scheduled to begin work on May 26.

The Downtown Seattle Transit Tunnel (Metro Bus Tunnel) is a 1.3-mile-long public transit tunnel that runs underneath downtown Seattle. Constructed between 1987-1990, the $455 million tunnel originally built for buses was updated in 2009 to include light rail access.

Caption information derived from captions written by Post-Intelligencer staff and attached to the back of the photograph.