Family members have identified the two people still missing after an explosion at a B.C. sawmill late Friday night, hours after police put the search on hold as the fire continued to smoulder.

A cousin said Carl Charlie, a father of two who worked at the mill for more than 20 years, is one of the men who hasn't been since the blast.

"He was a good young man, happy, go-lucky and free -- never let anything stress him out," Norman Charlie said.

"For me, I'm thinking in my mind (they should) go in there and find him."

An aunt identified the second missing man as Robert Luggi. He was also a father and grandfather, and was a member of the Wet'suwet'en First Nation.

Charlie was a member of the Babine Lake Nation. Another cousin, Charline Schmidt, said the fire chief has told her if the two men are still inside the burned-out facility, "they're deceased."

Police announced earlier Sunday that the search for the two missing workers was on hold while debris cooled after the massive blaze left 19 injured. A structural engineer must declare the site safe before rescue crews can explore the scene.

"Rendering the site safe is going to take a lot of effort. It's going to take outside agencies to come in and assist us," RCMP Const. Lesley Smith told CTV News Channel Sunday from the town.

"This has to be a meticulous search, and definitely a meticulous search, because we need to determine a cause and or locate any remains if there are any there," she said.

The cause of the blast and subsequent fire at the Babine Forest Products mill near Burns Lake Friday is under investigation, but workers inside the building reported smelling gas earlier in the day.

Investigators are talking to workers who were at the plant and still in the community, as well as outside witnesses, a process that could take some time, Smith said.

Smith said the scene she saw Saturday night as she drove into Burns Lake was shocking.

"I have to tell you that driving in (around 9:30) it was eerie, it was sad, it was devastating. All you could see is blackness and there were embers glowing where this massive structure used to be," she said.

"This community's going to be grieving for quite some time," Smith added.

A spokesperson for WorkSafe B.C. said investigators are gathering information about any previous workplace inspections that may have occurred at the sawmill.

Donna Freeman said about half a dozen WorkSafe officers, including an engineer, are in Burns Lake, but like emergency responders cannot get onto the site.

The blast occurred around 8:15 local time and witnesses described a number explosions followed by intense heat from the flames.

Police have said about 30 employees were working on shift at the time.

Sam Tom worked at the mill, but was outside when the blast occurred.

He heard at least five explosions, and the heat of the flames prevented him from going inside. He told The Canadian Press that he heard people screaming in pain and saw co-workers jumping out of a second-storey window.

"I had to help a couple guys, one with a broken arm, one (with) his body severely burned."

A spokesperson for the Northern Health Authority said five of the 19 injured workers were treated and released from hospital on Saturday. The agency issued a statement Sunday saying three of the injured who were admitted to hospital in Prince George have since been released.

The health authority did not offer an update on the conditions of the three patients sent to Vancouver or the two who were airlifted to Edmonton. Another patient is scheduled to be transferred to Vancouver on Monday.

Another patient is still in hospital in Victoria, while the rest are in hospitals in Vanderhoof and Prince George.

A published report from the Lakes District News said a fire caused by an "electrical failure" shut the mill down temporarily in March 2011.

Smith told The Canadian Press she was not aware of any safety concerns at the mill, and said safety protocols had recently been reviewed.

Job concerns

While the tragedy is weighing heavily on the minds of local residents, there's also concern the small B.C. town of 3,500 has lost its major employer.

The mill is located about 220 kilometres west of Prince George and employs about 250 people. But the economic impact of the operation in the community is substantial.

Burns Lake Band Chief Albert Gerow estimates about 30 per cent of the local economy is directly linked to the mill, and then there are numerous spinoff jobs.

"We're able to hopefully rebuild this sawmill, there's a variety of opportunities that we could look toward as time goes on," he told reporters at a news conference Saturday evening.

The mill is jointly owned by Burns Lake Native Development Corp. and Hampton Affiliates, a forest-products company based in Portland, Oregon.

Steve Zika, CEO of Hampton Affiliates, said with damage estimates coming in as high as $100 million, he's not sure if rebuilding is even a possibility.

B.C. Premier Christy Clark arrived in the community on Sunday, and admitted "it's hard to be specific" about the mill's future.

"I want to make sure that this community remains a vibrant forest-based community," she said. "And this mill has been the heart and soul of this community for a long, long time."

Bruce Disher, a welder who worked at the mill for 31 years, said the impact of losing the mill on the community would be "colossal."

"The whole town is basically Babine Forest Products," he said. "We have one other small sawmill, west of town. Probably 80 per cent of the jobs in Burns Lake end right here."

With files from The Canadian Press