SR99 tunnel

Bertha pushes past halfway point of tunneling for Washington’s SR 99
Bertha's repairs push Seattle's SR99 tunnel $200 million over budget. And it could get worse
avoiding struck-by incidents From our partners
As Bertha visits the dentist, a look at how this machine digs and builds the SR99 tunnel at the same time (VIDEO)
Board rules WSDOT should have given contractor more warning about pipe struck by Big Bertha before stall
Before Bertha repairs begin, archaeologists will test soil for artifacts
Tunnel-boring machine Big Bertha shut down for "months" due to complexity of needed repairs
Tunnel-boring machine Big Bertha moves forward 2 feet in test run to see if blockage is fully removed