A White Pass & Yukon Route Railway train derailed on a routine sightseeing trek from Skagway, Alaska, into Canada around 3 p.m. Wednesday and left at least nine people injured, according to the Alaska Division of Homeland Security and Emergency Management.

The cause of the derailment at Mile 20 was still unknown, the railroad said in an emailed statement to media Wednesday evening. Two vintage locomotives and four passenger cars derailed, the company said. It didn’t specify how long the train was.

“The location of the derailment is on a section of track that routinely handles thousands of passenger excursion trips across the scenic and historic White Pass & Yukon Route, constructed at the turn of the century,” the company statement said.

The railroad did not specify on which side of the Alaska-Canada border the derailment occurred. Zidek said Homeland Security believes it was on the Canadian side.

Skagway Visitors Center Director of Tourism Carlin “Buckwheat” Donahue said the train derailed near Summit Lake in British Columbia.

As of Wednesday evening, Zidek said, none of the injuries appear to be life-threatening.

“We are talking to the Department of Health and Social Services and some of the services they have in that area have not been requested,” he said. “Those folks are being well taken care of.”

According to Donahue, a Guardian medevac aircraft had been in the area and standing by.

The railroad said it has suspended operations on the White Pass & Yukon Route while the investigation into the cause of the derailment continues.

Donahue said the train departed at 12:15 p.m. and was en route back to Skagway when the incident took place. He estimated 150 to 200 people were on board.

Donahue expects crews to be working “24/7” to get the train operational once again and said it was still in the pass.

The White Pass & Yukon Route makes a 2,800-foot elevation gain through White Pass before crossing a corner of British Columbia and heading north to Whitehorse, Yukon.