THOMPSON, Man. -- A railway worker has died and another suffered serious injuries after rescuers spent hours trying to free them from the wreckage of a derailment in northern Manitoba.

The Arctic Gateway Group, which recently purchased the Hudson Bay Railway, said in a statement that authorities have confirmed the death, adding that a second employee sustained serious injuries from the wreck south of Thompson on Saturday evening.

RCMP said the man who died was 38 and was from The Pas, Man. The man who survived is 59 and is also from The Pas, police said, noting his injuries were life-threatening.

"On behalf of the entire Arctic Gateway Group, and all of our employees, our hearts go out to the families of these dedicated employees," Murad Al-Katib of AGT Foods, one of the group's partners, said in a statement.

The company said the train had three locomotives and several dozen railcars, some of which were carrying liquefied petroleum.

It said that based on information it has received, it believes that none of the railcars has been compromised and there doesn't appear to be any environmental danger.

Deputy Chief Selby Brown said the workers were trapped in the train for hours as first responders worked into the early hours of Sunday morning trying to free them.

He said the train went off the tracks on a washed-out trestle bridge in a swampy area at about 6:30 p.m.

The Arctic Gateway Group is a public-private consortium which bought the Hudson Bay Railway earlier this month from U.S.-based Omnitrax. Sections of the railway north of the derailment washed out in 2017 and Omnitrax had refused to make repairs, claiming the line was been losing money for years and would cost tens of millions of dollars to fix.

The railway is the only land link to Churchill, Man., a community of about 900 people on the shores of Hudson Bay, and crews have been working since the sale to try to reopen the connection before winter.

"We have said repeatedly that we will not compromise speed for safety and this is a stark reminder for us as we repair the northern section of the rail line to Churchill," Al-Katib noted in the company's statement.

Police said that officers were flown to the crash site, more than 500 kilometres north of Winnipeg, on Saturday evening and remained on scene until rescue personnel and specialized equipment could be brought in.

RCMP said that Transport Canada will investigate the derailment with assistance from police.

The Arctic Gateway Group said it is co-operating with the emergency services teams on site and will also be conducting a full internal review to determine the cause of the derailment.

The names of the workers were not released and the company said police were still notifying families on Sunday.