The tragedy that saw five snowmobilers killed in an avalanche last weekend in B.C. was preventable, says Avalanche Canada.

"Accidents like this are preventable, and I think this one was preventable," says Karl Klassen, the agency's public avalanche warning manager in Revelstoke.

The five men, all from Alberta, were snowmobiling with 12 others east of McBride when the large avalanche, triggered by the sledders, occurred. The men who died were Vincent Eugene Loewen, Tony Christopher Greenwood, Ricky Robinson, Todd William Chisholm and John Harold Garley.

While many of the snowmobilers had proper rescue equipment, several mistakes were made that made the tragedy worse, Klassen said.  

There were too many men on the slope at one time and three of the five killed were in a gully, the worst place to be in an avalanche, he said.  

"The fact that there's 15 or 16 or 17 people on the slope at the same time and involved in an avalanche, that alone is something we need to work on," he said.

Three of the five snowmobilers killed had deployed avalanche airbags designed to "float" along the surface of a moving avalanche, but the men were in a gully and were quickly buried.

"You need to do your planning and preparation work carefully to make sure you understand the conditions that you're going into," Klassen said.

"Things like going one at a time across a slope; not exposing more than one person at any time to a hazardous slope; avoiding terrain traps like gullies and benches where avalanche debris piles up very deeply, and even a small avalanche can have very serious consequences; and taking a more cautious approach in places like the North Rockies where information is scarce."

Klassen noted the majority of sledders on the slope that day had proper rescue equipment with them, and that the effort made by those on scene to rescue themselves and others was impressive, and prevented the loss of even more lives.

But more could have been done to prevent the tragedy in the first place, he said.

"I'd like to see everybody who goes into the mountains have an avalanche safety training course," he said.

"I'd like everyone who goes into the mountains to expose only one person on a slope at a time and not have multiple groups involved in the same location at the same time."