Photos Tod Fierner

The cheers and applause were barely audible above the grinding of rock and the growling of the engine as the tunnel excavator dug into the concrete and rock at the east portal of the Caldecott Tunnel, signifying the start of tunneling at the Fourth Bore Project, a four-year, $420 million project. Upon completion, the new northern bore and the existing northern bore will carry westbound traffic, while the two southern bores will carry eastbound traffic. L. Borrowman