Workers were forced to jump from the second-storey as their colleagues on the ground fought desperately to push their way in to rescue others after the sawmill they were working at was blown apart by an explosion and fire.

Nineteen people were sent to hospital, some with critical injuries, and two were still missing Saturday as uninjured employees drove their burned colleagues to hospital and other members of the close-knit communities nearby rushed to the hospital to help out.

"I had to help a couple guys, one with a broken arm, one (with) his body severely burned," Sam Tom told The Canadian Press on Saturday, still emotional after a night of horror and no sleep.

Tom said he was just coming back from a coffee break when he saw a flash.

Then "boom. Everything just went flying," he said, struggling to describe it further.

Tom said his job was outside the mill. When the explosion happened, he said, he parked the loader he was driving and tried to run into the mill, but the flames were too hot.

"I couldn't even make it in there," he said. "Everything was burning."

Tom then tried to get into the mill through a blown-out wall, but debris was everywhere.

"Everybody was yelling, so (I) followed the yelling noise, then we got one guy out and more guys started coming out."

Co-workers jumped from the second-floor of the building. Some people were screaming in pain.

"There was no time to think," said Tom.

Two people were still missing Saturday morning, hours after the blast Friday evening at about 8:15 p.m. at the mill, Babine Forest Products, a company located on leased aboriginal land just outside Burns Lake.

Rescue efforts were further hampered by blowing snow, whiteout driving conditions and temperatures that dipped to -20 Celsius.

Burns Lake is about 228 kilometres west of Prince George.

Steve Raper, spokesman for the Northern Health Authority, said 19 people were taken to hospital with a variety of injuries. Some of the injured have severe burns and four are in critical condition.

Neither Raper nor the RCMP spokeswoman would say if anyone had been killed.

"The hospital had to deal with multiple burn injuries," said Albert Gerow, chief of the Burns Lake Band.

"They also had to deal with an incredible snowstorm in the community. . . It was snowing quite heavily throughout the night. it made even travel on the roads very hazardous."

Raper said after the explosion, two were airlifted to Vancouver General Hospital and two to Edmonton's University Hospital. A fifth person was transferred to Vancouver later on Saturday but was considered in stable condition.

Nine others remain in hospitals in Smithers, Vanderhoof, Prince George and locally. Five were treated and released.

Susan Schienbein, a long-time councillor in Burns Lake, said she headed to the hospital as soon as she heard of the explosion.

She was there -- along with many others community members who had done the same thing -- through the night.

"We care about these people. They are our friends, our neighbours, our family," she said.

There was no official word on what caused the explosion, but community leaders were hearing anecdotal reports from workers who smelled gas.

"It was a gas explosion," said Wilf Adam, chief of the Babine Lake First Nation where many workers are members.

"The morning shift said that there was a big gas odour coming from the basement, and when the afternoon shift came on, that's when it happened."

Some injured workers who had been released from hospital gathered with their family, friends and co-workers at a community hall located on the reserve.

Adam said the facility was being used as a command centre to provide grief counselling and general updates on what was happening at the still-smoldering mill.

"We're still waiting for the fire to go out at the mill, so there will be an investigation of what happened and we'll see if we can have any closure for the two that are missing," he said.

"It's devastating to the town, it's one of our biggest employers, and our thoughts are with the people who are injured."

The mill is a joint venture with the Burns Lake Native Development Corp. and Portland, Ore.-based forest products company Hampton Affiliates.

Scott Gascho, the sales manager for the mill, said from Oregon the company is working on a response.

"This is obviously a tragic situation for the Burns Lake community and our company," he said. "I am sure our president will be releasing a comment in the next day or two."

An online news story from the Lakes District News noted a fire on March 1, 2011 shut down the mill for some time.

A spokesman for the mill had said an electrical failure was to blame and described the fire as "significant."

RCMP Const. Lesley Smith said the mill employs 250 people and there were about 30 on shift at the time of the explosion. She couldn't comment on the reports of gas on scene.

"What I understand is there was a big fireball," she said.

"As a result of that fireball, other things started exploding, so I'm assuming it was equipment related to a product mill."

Megan Benson, 24, lives about 10 minutes from the mill.

Though she didn't hear the explosion itself, she saw smoke rising from the mill on Saturday.

"I could smell it from our house. And you could see the smoke."

Benson said alongside worries about the wounded came those about the mill itself, a strong presence in the community of about 10,000.

About a quarter of the town is connected to the mill in some fashion, she added.

"People are scared," she said. "That's our livelihood ... that's how we feed our family."

Chief Gerow sits on the board of Babine Forest Products. He said the company is a unique partnership of the Burns Lake Native Development Corporation -- an entity that comprises six area bands -- and Hampton Affiliates.

It was created in 1974 and is a key employer for aboriginal and non-aboriginals alike in the area, he said.

"It has a huge economic impact on our community. There would be a strong desire to be rebuilt."

Burns Lake Mayor Luke Strimbold said the community is "in the midst of dealing with a serious incident.

"This is a difficult time for our community and we need to pull together to ensure we provide the best support possible," he said in a statement.

"Every individual, their families, and all those involved are in our thoughts."

Premier Christy Clark said her government's thoughts and prayers are with the injured and their families. She also lauded the efforts of community and emergency officials.

The provincial Forest Practices Board conducted an audit of Babine Forest Products last fall and said in a news release from earlier this month that the company "showed a high standard of forest operations."

The audit dealt with the company's woodland operations. The news release made no mention of the sawmill.