For the first time since December 2013, Bertha on Jan. 7, 2016, drove out of the access pit, but a listing barge and a sinkhole on the same day prompted Inslee to step in and shut down the Washington State Dept. of Transportation-owned project.

On Tuesday, Jan. 12, and about 190 ft into the new wave of tunneling, a soil-removal barge, which had received Bertha-excavated material via a conveyer belt, started listing at Terminal 46. To prevent damage to the conveyor system, Seattle Tunnel Partners (STP), the joint venture operating the project, released the barge from its moorage, spilling clean soils into Elliott Bay and sending the barge into nearby Pier 48, a WSDOT-owned pier slated for demolition. The tunnel excavation temporarily stopped as crews moved the barge, started transferring material to another barge, worked to bring in a third barge and initiated inspection on the two terminals for damage.

While work continued on the barges and piers, STP started mining again at 7 p.m. that same evening, using trucks to remove excavated material. Two hours after tunneling restarted, a sinkhole developed within the contractor’s work zone near South Main Street, about 35 ft north of the 120-ft-deep access pit that crews used to access Bertha’s cutterhead for the lengthy repairs. The sinkhole was more than 100 ft south of the cutterhead’s current location in ground that crews mined through a week prior. It measured about 35 ft long, 20 ft wide and 15 ft deep.

The sinkhole was filled overnight with 250 cu yd of concrete.

Then, WSDOT chose to “suspend for cause” all tunneling operations involving the tunneling machine or loading of barges. STP must complete a detailed analysis and modify tunneling operations to ensure appropriate ground control before the agency will allow tunneling to resume.

“In light of recent incidents on the SR 99 Tunnel Project, WSDOT is notifying the contractor that they must suspend tunneling work for cause,” Lynn Peterson, secretary of transportation, said in a statement. “I share the Governor’s concern for public safety and we want to ensure that the contractor has the right protocols in place to proceed with their work safely.”

WSDOT requires the contractor to conduct complete root-cause analyses and take appropriate steps to ensure that issues such as the sinkhole don’t happen again. “STP will not be allowed to resume tunneling until [its] analysis and work plans meet the satisfaction of our experts,” Peterson says.

Inslee announced the stoppage at a press conference, saying his concern regarding public safety requires the contractor to address the root causes of the sinkhole.

“We need to be assured that this is not going to happen underneath the viaduct with obvious ramifications that could be very, very concerning or under the city of Seattle,” he says. “We are legitimately disappointed.”

Inslee says STP stopped its soil-monitoring protocols when Bertha stopped tunneling and did not restart them when Bertha started moving again. “I don’t understand that decision at all,” he says.

STP has not commented on the latest issues.

Washington State Sen. Michael Baumgartner (R), an opponent of the tunneling project for several years, has stepped up his effort to cancel the tunnel project and, instead, repair and upgrade the existing viaduct. He says he will soon propose legislation in his ongoing fight against a project he says hurts taxpayers.

For a project slated to open in late 2015, even a revised April 2018 date hangs as more of a question than an answer.