A nearly six-year-long legal battle drew to a close Thursday when attorneys made their final arguments on whether Texas oil company Tesoro is responsible for an explosion that killed seven workers at its refinery in Anacortes, Washington, in 2010.
"From the time it took over the refinery in August of 1998 up through the time of the explosion, April 1, 2010, Tesoro suffered from an infection of systemic safety apathy," assistant attorney general Brian Dew argued on behalf of the Washington Department of Labor and Industries.
The explosion rattled houses miles away and lit up the night sky over the coastal town in what turned out to be Washington's worst industrial accident in half a century.
The blast also led the Department of Labor and Industries to levy a $2.4 million dollar fine, the largest in the agency's history, against Tesoro. The company has been fighting that fine before Judge Mark Jaffe of the Washington Board of Industrial Insurance Appeals for the past half-decade.
To date, in preliminary decisions, Jaffe has knocked $1.9 million off Tesoro's fine, down to a half-million dollar fine.
Dew said Tesoro failed to keep the silo-sized devices known as heat exchangers operating within the safe zone of pressures and temperatures to avoid corrosion. That safe zone is defined by what is known in the industry as a Nelson curve.
Federal investigators with the U.S. Chemical Safety Board determined in 2014 that a type of corrosion known as high-temperature hydrogen attack led to the deadly explosion.
Tesoro attorneys said Thursday the company acted in good faith to protect worker safety and to operate within the Nelson curve.
"Tesoro was doing what it was supposed to be doing," San Francisco attorney Peter Modlin with Gibson, Dunn & Crutcher argued on Tesoro's behalf.
He said the company was "extremely conservative" in its handling of corrosion inside the giant metal towers that heat oil to 500 degrees Fahrenheit or more.
Modlin said Tesoro followed industry standards and the advice of the outside corrosion experts it hired.
The Chemical Safety Board investigation faulted industry standards, weak regulations and Tesoro's "complacent" attitude toward safety.
"The board and the investigators are absolutely unified in our commitment to worker health and our disgust and exasperation with the status quo," Beth Rosenberg, Chemical Safety Board member, told an Anacortes audience when the agency's investigation was released in 2014.
After Thursday's hearing, both sides declined to comment.
"It shouldn't take six years," said Butch Cleve, Tesoro-Anacortes machinery operator and United Steelworkers Local 12-591 safety representative. "We still don't have a real resolution to the explosion, the deaths of seven people."
Cleve said safety at the Anacortes refinery has improved in some ways since the explosion.
He said, in other ways, safety has gotten worse, partly because so many workers have left. He estimated as much as a third of the workforce has departed since the 2010 explosion.
"Some of it is stress," he said. "Some of it's just the images that come with being in that area and seeing that equipment. For a lot of folks, memories of that night were just too difficult, I think."
Judge Jaffe said he plans to issue a decision on the Tesoro case by September.