VANCOUVER — Four people died and several others were rescued from the sites of two separate avalanches in northern British Columbia over the weekend, police say.In the first incident Sunday afternoon, an avalanche on the Iridium Shoulder ski run on Mount Knauss north of Terrace struck four heli-skiers. Three were killed and their bodies recovered from the mountain, while a fourth was airlifted with serious injuries and taken to hospital, Terrace RCMP said.A short time later and more than 1,000 kilometres away, a separate avalanche near the B.C.-Alaska border — close to the Klehini River and Atlin — claimed the life of one more skier. At least one other person was rescued from that slide with injuries.The BC Coroners Service is investigating both incidents..Police have not identified the heli-ski operator involved in the Mount Knauss avalanche.Avalanche fatalities in British Columbia have averaged about seven per year over the past decade-plus, according to data from the BC Coroners Service.Between January 2011 and April 2022, the service recorded 77 avalanche-related deaths across the province, although numbers fluctuate significantly from year to year depending on snowpack and backcountry use.