04/25/2012 03:39 EDT | Updated 06/24/2012 05:12 EDT

Lakeland Mills Explosion Dead: Second Worker Dies Of Injuries After Sawmill Blast, Fire (VIDEOS, PHOTO)

VANCOUVER - A tiny insect that's devouring British Columbia's forestry industry is now being fingered by industry and union officials as a key suspect in the deadly explosions of two sawmills over the past three months.

Workplace safety officials have been cautious about saying the explosions in Prince George and Burns Lake could have been caused because the process of milling beetle-ravaged wood might be somehow more combustible.

But on Wednesday, industry, government and union leaders agreed the first step towards preventing another occurrence involves scrutinizing the role the dry timber may play in the sawdust buildup that appears to be a common denominator in both catastrophes.

"It's basically the challenge of responding to the mountain pine beetle," said John Allen, present of the Council of Forest Industries, which represents more than 50 B.C. sawmills.

Timber is older, dryer and more brittle than ever before, he said.

"Up until earlier this year, the issue in front of us was how to saw lumber from dead trees. Now we've experienced these two sawmill explosions and fires ... we now have this safety issue on our hands."

The industry has been sawing dead wood for three decades, but the occurrence of two massive explosions inside mills in such a short time frame means something is different and that must be investigated, said union official Steve Hunt.

"What we do know is in common with both explosions is they were sawing wood in a different method. It's dryer wood," said Hunt, Western Canada director for the United Steelworkers.

"We don't know if that's the cause, but as a precautionary measure that's a good place to start."

Two people died as a result of the blast and fire that ripped through the Lakeland sawmill on Monday night. The Coroners' Service confirmed Wednesday that Glenn Francis Roche, 46, died in Edmonton after being transferred there for treatment of critical burns.

Alan Little, a 43-year-old shift supervisor, died Tuesday morning in Prince George. The men were among 11 severely injured in the disaster at the Sinclar Group Forest Products operation.

In mid-January, two workers were killed when a fireball slammed through the mill in Burns Lake and it burned to the ground.

Three victims were also airlifted to hospitals in Vancouver and Victoria, while six people remain in Prince George hospitals and 13 others have been treated and released.

Labour Minister Margaret MacDiarmid said sawmills across the province will be handed orders Thursday with directions around cleaning up and managing accumulating dust, as well as addressing potential ignition sources.

"We need plain language. If we're going to deal with dust, what are the best ways we can do that? If we're looking at ignition sources, what kinds of things can we look for?" MacDiarmid said.

She said a working group is also being formed with representation from the union, industry and WorkSafe BC to look at best practices for dealing with potential factors in the explosions.

According to an inspection report issued Feb. 9 by WorkSafe BC, dust has been an issue at the Lakeland mill, although concentrations were below the exposure limit and the agency issued no orders.

"There are accumulations of piles of wood dust in various areas of the mill," wrote Kim Hess, an occupational hygiene officer, in the report. "We reviewed the requirement to prevent the accumulation of hazardous amounts of wood dust."

The issue of wood dust also arose in an inspection report issued Feb. 3, 2009.

The report stated wood-dust exposure should be re-evaluated because of changes in productivity and "the fact the majority of the wood being processed is dry beetle killed pine."

Allen said he's surveyed all the council's members since then and found they've all taken extra safety measures, including monitoring hotspots where there's a possibility a spark might meet dust.

"These are preventative actions. I can tell you all the companies I've talked to are taking this very, very seriously," he said.

"I would expect those efforts will ramp up even more so."

Efforts will begin in sawmills, but likely expand to other processing facilities where dust might be an issue, he added.

But the industry will not stop using the wood, he said. Instead, industry is calling on the government to establish an economic recovery plan as timber supplies are depleted.

He said the pace of investigations, which could take months to determine the exact cause of the explosions, was moving as it should.

"I don't think there's much more WorkSafe could have done," he said about getting preliminary findings out that may have prevented the latest explosion.

Hunt said the working group will attempt to gather research that might spell out what's changed in timber that's been successfully processed without major incidents for years.

"What's new is the method. They're trying to increase the cut, maximize the cut, so the sawdust is finer," he said. "Is there a different property in the sawdust that we haven't seen before?"

The union will also direct its membership to take extra precautions towards proper dust evacuation and ventilation.

"Even if we have to over-regulate right now, so be it."