Preliminary investigations into Monday’s avalanche which killed three heli-skiers shows Tyax Heli-skiing took all the standard safety precautions prior to the accident, RCMP say. Wednesday, RCMP were reviewing a copy of a video shot just prior to the accident and of the rescue efforts as part of their continuing investigation. The avalanche occurred at about 2:45 p.m. Monday near the toe of the Spearman Glacier, north-east of Blackcomb. Five skiers in a group were hit by the avalanche, which came from a side slope. Three skiers, 45-year-old Michele Rubli of Switzerland, 33-year-old Wolfgang Bichlmeier of Germany and 30-year-old Josef Wembacher of Germany were all buried under 1.5-2 metres of snow. The other two skiers were not buried; one received minor injuries. Tyax Heli-skiing President Mike Jakobssen was leading the group of skiers. He said the three buried skiers were located in less than five minutes through the use of Pieps avalanche transceivers. Although rescue efforts were begun immediately it still took nearly 40 minutes to dig the three skiers out of the packed avalanche debris. The bodies were flown to the Whistler Health Care Centre where they were pronounced dead on arrival. Autopsies performed Tuesday at Vancouver General Hospital showed all three died of suffocation and crush asphyxiation. Some local ski patrol and officials at the provincial avalanche centre have suggested a weak layer in the snowpack caused by a November rain may have been at least partly responsible for the avalanche, although RCMP said Wednesday they were still investigating the scene of the accident and had no data on the snow profile at the time of the accident. The avalanche rating for the Whistler/Blackcomb area at the time of the accident was moderate. The avalanche was upgraded from earlier reports of a Class 2 to a Class 2.5 on Wednesday. Class 2 is categorized as big enough to bury a person but not big enough to bury a car. The skiers were on their fifth and final run of the day when the avalanche occurred.