COLUMBIA ICEFIELD, ALTA. -- The president of the company that runs the bus tours at the Columbia Icefield between Banff and Jasper said changes will be made, if necessary, after a rollover on the glacier killed three people and sent two dozen to hospital.

The cause of the accident hasn't been determined. The off-road bus rolled off the road to the glacier Saturday afternoon and came to rest on a rocky slope, its six huge tires pointed up at the sky.

The RCMP, Occupational Health and Safety and the Transportation Safety Board spent Sunday milling about the vehicle, which slid about 50 metres down a steep embankment coming to rest near the glacier.

It's unclear how soon it will be removed from its current location but an internal investigation is underway as well.

“We started right away to review what happened, what is our process with our protocol at every step and so we're doing that internally but we are also working with the external teams to ensure that gets a fulsome review,” said Dave McKenna, the president of the Banff Jasper Collection by Pursuit, which operates the tours and its fleet of 22 vehicles.

The RCMP said the cause of the accident still isn't known and the snow coach, called an Ice Explorer, will receive a full mechanical inspection.

The red and white big-wheeled buses regularly take tourists up a rough rocky road onto the Athabasca Glacier in Jasper National Park.

In all, 27 people were aboard when it crashed.

Alberta Heath Services said, of the 24 survivors, 14 had life-threatening head or pelvis injuries. Five others were in serious condition with broken bones and the remaining five suffered minor injuries.

McKenna said the Ice Explorers are offroad vehicles and seatbelts are not required. They aren't allowed on highways and have a top speed of 40 kilometres an hour.

He said once the investigation is complete, Pursuit will implement any changes that might be part of recommendations for things like seatbelts.

“We will wait until the investigation is over and we will listen to all the recommendations and anything we're required to do.”

Tours have been offered on the glacier since 1969 and the current type of Ice Explorers have been used since the early 1980s but are constantly upgraded.

“We average about 480,000 visitors a year and we've been operating these vehicles since the early 80s. We've had over 16 million passengers safely taken out on to the ice over all these years. No major incidents,” McKenna said.

“Over 39 years of course there's a few bumps but nothing serious with fatalities or critical injuries.”

Angela Bye was on one of the coaches just before Saturday's accident. She said she never worried about her safety.

“We were in the exact same vehicle, hours before. It's like being in a school bus with really tall seats. The seats are way more padded than a school bus. They explained how it ran. How the wheels work,” she said.

“I felt very safe.”

This report by The Canadian Press was first published July 20, 2020.