RCMP say three passengers were killed when a glacier sightseeing bus rolled over at one of the most popular attractions in the Rocky Mountains, the Columbia Icefields.
Cpl. Leigh Drinkwater says there were 27 passengers on the vehicle when it crashed.
Drinkwater says getting updates from the scene is difficult, due to unreliable cellular service in the mountains, but he says the ice explorer apparently rolled, and that a number of critically injured patients were taken to Calgary by air and ground ambulances.
The iconic red and white coaches, which look like buses with monster-truck tires, regularly take tourists up a rough road onto the Athabasca Glacier.
Tanya Otis, a spokeswoman for Pursuit, the company that runs the ice explorers, says one of the off-road vehicles overturned early in the afternoon on its way to the Athabasca Glacier and that the company is supporting the efforts of first responders.
STARS air ambulance spokeswoman Fatima Khawaja had no further details on injuries, but says it sent choppers from its bases in Edmonton, Calgary and Grande Prairie.
The Columbia Icefields are one of the largest non-polar icefields in the world. They are located about 100 kilometres south of Jasper and are accessed from Highway 93, the Icefields Parkway.
RCMP say the investigation was in the preliminary stages, and updates would be provided as they became available.