Families of seven workers, including two from Oak Harbor, who were killed in the 2010 explosion at Tesoro’s Anacortes oil refinery, have settled a lawsuit against the oil companies.

Attorney David Beninger said the families of the seven workers killed, as well as an injured contractor, will split the approximately $39-million settlement from Tesoro, Shell Oil and Equilon.

The court will decide how the money is divided.

Oak Harbor residents Matt Gumbel, 34, and Donna Van Dreumel, 36, were among those killed in the explosion. The other victims were Daniel Aldridge of Anacortes, Matt Bowen of Arlington, Darrin Hoines of Ferndale, Kathryn Powell of Burlington and Lew Janz of Anacortes.

A separate suit against Lloyd’s Register Energy, a company hired to examine equipment, is ongoing. Beninger said the company inspected the refinery equipment 18 months before the explosion and claimed it needed no further testing.

The Seattle Post-Intelligencer website reported this week that a draft report on the explosion by the U.S. Chemical Safety Board concluded the tragedy could have been prevented if safer equipment construction materials had been used.

Investigators with the state Department of Labor and Industries also concluded after an investigation in 2010 that the blast could have been prevented.

L&I fined Tesoro a total of $2.38 million and cited the company for 39 “willful” violations and five “serious” violations of state workplace safety and health regulations. It is the largest fine in the agency’s history.

L&I found that the explosion occurred in the plant’s Naphtha Hydrotreater Unit as workers were returning a bank of nearly 40-year-old heat exchangers into service after they were shut down for maintenance. One of the heat exchangers split violently.

A lab found cracks in the heat exchanger that exploded, along with “at least one other” unit; the investigation found that the heat exchangers were never tested in a way that would have revealed the problem, the L&I concluded.