SEATTLE – Gov. Jay Inslee said Thursday he has ordered a halt of tunneling for the new State Route 99 after a sinkhole formed behind the boring machine, Bertha.
Inslee said he is ordering tunnel contractor Seattle Tunnel Partners to stop drilling until safety can be guaranteed.
"I have great concerns regarding public safety if the contractor were to move forward without addressing the root causes of this sinkhole. We must continue to protect the public safety," said Inslee.
WSDOT says STP is being informed the stop order is a "suspension for cause" in contractual terms.
"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," said Washington Transportation Secretary Lynn Peterson in a statement. "We are asking that the contractor complete root cause analysis and take the appropriate steps to ensure that incidents, such as the sinkhole near the repair pit, do not occur again. STP will not be allowed to resume tunneling until their analysis and work plans meet the satisfaction of our experts."
Senator Curtis King, R-Yakima, chair of the Senate Transportation Commission did not think the stoppage was necessary.
While King said the contractor needs to be held accountable, he called the timing of the announcement a "strange coincidence."
Inslee announced the stop work order immediately following a press conference held by Republican senators questioning the independence of the state's investigation into the mistaken early release of thousands of state inmates.
The hole developed Tuesday around 9 p.m. where dirt was being excavated just north of the access pit where Bertha was repaired.
Seattle Tunnel Partners' Chris Dixon said the sinkhole was 35 feet long, 20 feet wide and 15 feet deep. It has been filled with 250 cubic yards of concrete.
The cause of the sinkhole is still under investigation. STP said there is no indication that any other locations have experienced ground loss.
Dixon said that this section of the project, before the machine goes under the Alaskan Way Viaduct, has always been considered a testing phase.
But the sinkhole is the latest problem the project has faced. Bertha started moving again Dec. 23 after being idle for two years for repairs.
A barge used to haul dirt from the construction partially tipped Tuesday, forcing STP to stop digging. Then, the sinkhole happened.
The order by Inslee comes at a critical juncture for Bertha. It is scheduled to bore under the viaduct in March, forcing the elevated structure to be shut down to traffic for two weeks.
The tunnel was initially supposed to open to traffic late last year. It's now scheduled to open in April 2018.