the Highway 99 tunnel boring contractor sought 600 million dollars in court, because the project was 2.5 years late, and $600M over budget, and due to damage to Bertha the boring machine when it hit a state owned pipe that wasn't in the disclosure

STP and WSDOT squabbled over a buried steel pipe that tunnel-boring machine Bertha struck in December 2013, and whether WSDOT adequately disclosed its presence to STP in geotechnical reports.

STP project director Chris Dixon claimed the state-owned pipe caused Bertha to stall and kicked off a massive operation to replace cracked gears and bearings. The giant drill finally completed the dig from Sodo to South Lake Union in April 2017, about 2½ years late. WSDOT’s lawyer said in court the pipe was no more significant than a toothpick to the world-record 57-foot-wide cutting disc.

Years before, WSDOT plunged the 119-foot-long steel pipe, known as “Test Well 2,” into Seattle’s waterfront soil to measure groundwater that might flood some future tunnel construction project. WSDOT abandoned the pipe in 2002

A state appeals judges upheld a jury verdict against contractor Seattle Tunnel Partners.

Jurors determined that WSDOT did provide enough notice to STP about underground conditions, so the jury never reached their second key question of whether a steel pipe was the cause of Bertha’s damage.

https://www.seattletimes.com/seattle-news/transportation/wsdot-notches-another-legal-win-over-highway-99-tunnel-cost-overruns-after-bertha-hit-pipe/