The resulting fire gutted the mill and put 250 employees out of work.
The Criminal Justice Branch sifted through hundreds of photos, exhibits and interviews before reaching its decision. Provincial Crown counsel spokesperson Neil Mackenize says WorksafeBC didn't follow the rules for conducting a criminal investigation and that would likely result in a significant amount of evidence having to be thrown out.
"The Crown concluded that what had begun as a WorkSafe safety inspection of the mill evolved into an investigation. From that point on, certain evidentiary rules would have come into play."
Those rules include obtaining a search warrant to gather evidence, and warning officials of their rights.
Lake Babine chief disappointed
The chief of the Lake Babine Nation, Wilf Adam, says he's disappointed there won't be any charges.
"Somebody needs to be brought to justice over what has happened. You know, two people have died. And a lot of lives have changed because of it."
Adam says the community is still searching for some resolution to the tragedy.
Following the fire and explosion, the B.C. Safety Authority, an independent agency that monitors the safety and licensing of technical systems and equipment, investigated and issued nine recommendations about wood dust management. It also called for improvements to natural gas and propane codes.
At the time it said it wasn't releasing its full report because Crown counsel was reviewing a referral on the mill explosion from WorkSafeBC, the agency that enforces workers' safety.