Train derails in western Man.

Investigators and workers with CN Rail were kept busy Thursday after a 56-car train derailment in western Manitoba, RCMP said.

The eastbound cars, carrying potash headed to a destination in the U.S., came off the tracks 16 kilometres west of Rivers, Man., at about 9:30 a.m. CT, according to police.

'It sounded like the train was actually coming into the elevator.' —Trevor Peters, witness

CN Rail said the train was 99 cars long, all except the locomotive containing potash.

There were no injuries reported.

Many of the rail cars are ripped open and scattered their loads along the tracks, said Lorne Green, the CEO of the Rural Municipality of Daly.

Green described the scene as a "mangled heap" of wreckage.

Trevor Peters works at a grain elevator not far from the derailment scene.

He said he and a few co-workers heard a huge noise and scrambled to a nearby window.

"Sure enough, we saw all the cars piling up, just running into each other. We definitely knew something was wrong," Peters said.

"It sounded like the train was actually coming into the elevator," he added.

Peters said CN Rail crews have brought in heavy equipment and are working furiously to separate the mangled cars.

A CN Rail spokeswoman told CBC News the company has been diverting other trains onto a separate east-west rail line for the entire day. She couldn't comment on how long the derailment would take to clean up.

Officials with Canada's Transportation Safety Board have been called in to investigate, the spokeswoman said.

Rivers is located about 250 kilometres northwest of Winnipeg.

Olympic attendees stranded

Passengers aboard Via Rail trains bound for Vancouver were stuck in Winnipeg because of the derailment, a spokesperson for the Crown corporation said.

Officials confirmed that some stranded passengers were destined for the Vancouver Olympic Games, which begin Friday.

They arrived in Winnipeg headed west at 8 a.m. local time Thursday, but it wasn't known when their trip will resume because of the derailment, a Via spokesperson said.

Passengers were set to leave at noon, but were told about the derailment and subsequent delay at 12:30 p.m., according to passenger Morgan Hapeman.

Hapeman, who is headed to the Olympics and has been on the train since leaving her upstate New York home on Tuesday night, was taking the delay in stride.

"It's an adventure," Hapeman said. "What can you do? Just go with the flow," she said.

Hapeman said Via Rail officials have been diligent about keeping passengers informed about the delay.

"I think the information is very good ... as soon as they knew, they passed it on to us," she said.

Hapeman said the first Olympic event she has tickets for is on Sunday.