Employees of two British Columbia sawmills destroyed by fire in 2012 have launched a class-action lawsuit against the provincial agency responsible for workplace safety.

The separate fires in Burns Lake and Prince George killed a total of four workers and injured 42 others.

A notice of civil claim filed in B.C. Supreme Court says combustible wood dust fuelled the January explosion at Babine Forest Products and an April explosion at Lakeland Mills Ltd.

The employees and family members allege WorkSafeBC was negligent in its inspections and investigations of the mills, breached its fiduciary responsibilities to the workers, causing them physical and psychiatric injuries.

The allegations have yet to be tested in court.

The plaintiffs are seeking general, special and punitive damages, as well as declarations that the inspections and investigations were negligent and the agency infringed on their charter rights.

“The class members trusted WorkSafe to take all reasonable steps to ensure the safety of the mills and to competently investigate the explosions,” says the statement of claim.

“By failing in both respects, WorkSafe betrayed the class members’ trust; denied them justice for their suffering and for the suffering and deaths of their loved ones; undermined their faith in government; and robbed them of the sense of security and safety that a trustworthy and competent system of prevention and deterrence provides.”