A Thurston County jury is hearing arguments in the case that could put Washington state and taxpayers on the hook for $300 million in damage and delays.

OLYMPIA, Wash — The trial to determine who is to blame for the construction delays of Seattle's State Route 99 tunnel and cost overruns started Thursday in Thurston County.

Jurors heard opening statements in the trial that's pitting Washington State Department of Transportation (WSDOT) against Seattle Tunnel Partners (STP).

The state wants STP to pay nearly $60 million for delays to the project.

STP said the state, and potentially taxpayers should be on the hook for more than $300 million in damage and delays.

Washington State Department of Transportation attorney David Goodnight argued STP violated its contract by the state by failing to properly train its workers. Goodnight also said STP didn’t test or operate the tunnel boring machine, known as Bertha, properly when digging began in 2013.

“Each of these contract provisions are mandatory, and they’re all included for very important reasons. And every one of them was violated,” said Goodnight. “STP was cutting corners.”

Goodnight said those practices caused Bertha's breakdown in December of 2013.

But John Dingess, attorney for STP, told jurors a much different story.

“None of that had anything to do with the damage that occurred to the TBM [tunnel boring machine],” said Dingess. He told jurors the machine broke down after it hit a buried steel pipe.

The state buried the pipe in 2002, but Dingess said the state didn’t inform STP about it until after Bertha struck it.

Dingess said the state should have to pay for the damage to Bertha and subsequent delays to the project, which he said would be “in excess of $300 million.”

The state’s attorney told jurors the evidence will show the pipe had nothing to do with the breakdown, adding that STP was warned about the pipe, and forgot it was there.