CALGARY, Alberta (Reuters) - A Quebec man skiing in the back-country wilds of Banff National Park this week was the latest fatality in what has been an extraordinarily deadly start to the winter avalanche season in the mountains of Western Canada.
The 19-year-old man was skiing with a companion near Lake Louise, Alberta, on Monday when they triggered an avalanche. The man died while being airlifted to a hospital.
He was the fourth avalanche fatality in Western Canada in a two-day stretch and the 10th of the season, a tally experts say is unparalleled.
"It is unprecedented for this early in the year," said Mary Clayton, spokeswoman for the Canadian Avalanche Centre. "It's staggering."
Among those killed was a 21-year-old Australian man who died on Sunday while snowboarding at a ski resort in southern British Columbia. That was the first avalanche death on an in-bounds area of a Canadian resort in 25 years, Clayton said.
Over the past 10 years, Western Canada has had an average of 14 avalanche deaths each winter. However, the early months of the season are usually more benign, with most of the fatalities occurring later in the winter, according to the Avalanche Centre.
The season became particularly vicious for back-country skiers and snowmobilers after a "Pineapple Express" -- warm, moisture-laden air from the Pacific Ocean -- pushed into the mountains of southern British Columbia, bringing rain that reached high altitudes and created a crust of ice.
That ice now has a layer of granular snow on top of it that is covered with a meter (3 feet) or more of lighter snow that is prone to slipping.
"It's weak and it's deep," Clayton said. "Maybe a number of people could ski on it until someone hits a sweet spot and it goes."
In the vast back country of Banff National Park, popular with international tourists and day trippers from booming Calgary, Alberta, the avalanche risk is rated "considerable."
"Conditions in the park are touchy right now," said Grant Statham, a mountain risk specialist at Parks Canada. "But they are not as bad as they can get."
Statham said Banff has been experiencing what he called a typical year for avalanche risk, but this has followed several years of good conditions.
"People with just a few years under their belt may not have seen conditions like we have this year, even though we consider this quite normal," he said.
Police in the ski resort of Whistler, British Columbia, are weighing criminal negligence charges against a snowboarder injured on New Year's Day, when an avalanche swept him and another man off a 50-meter cliff. The other man died.
The men ignored warning signs and went into an area that is permanently off-limits to skiing because of its danger.
Clayton said the record for Canadian avalanche deaths was set in March 1910, when 58 railway workers attempting to clear snow off a track in Rogers Pass, British Columbia, were buried in a slide.
The worst recent winter was 2002-03, when 29 were killed in avalanches, including seven teenagers from Calgary who were on a school ski trip to a national park in British Columbia when they were buried by a snow slide.
Additional reporting by Allan Dowd; Editing by Peter Galloway