EDMONTON -- A snow coach that rolled in a deadly crash on the weekend was removed from the rocky slope on Tuesday.

The process took more than a day, using heavy equipment, cables and a bulldozer to move it.

It was towed away on a flatbed trailer, covered to protect it so a mechanical inspection can be completed off-site. Police say the investigation will be a slow and careful process.

The July 18 crash that killed three people and injured dozens more is still under investigation by the RCMP, the Transportation Safety Board and Alberta Occupational Health and Safety.

As of Monday, four people were still in critical but stable condition. 

Banff Jasper Collection by Pursuit, the company that operates the tours, is doing its own review. President Dave McKenna said once the investigations are complete, Pursuit will implement any changes that are recommended.

The province says there have been no previous OHS complaints involving the tour company in the last five years.

The ice explorers are off-road vehicles designed to operate on the glacier's slick terrain.

"This is very steep terrain, there are opportunities for the bus to be out of control," Ahmed Shalaby with Safer Roads Canada told CTV News Edmonton. "If this happens you will want to have additional layers of safety such as restraints or seatbelts so that the passengers are confined to their seats."

According to Pursuit, the vehicles do not have seatbelts as they are not licensed to be on the road and do not exceed 40 kilometres an hour.

RCMP say the investigation could take weeks to months to complete.

With files from CTV News Edmonton's Sarah Plowman