One of the four people who were found in the avalanche that swept a ski slope in the Swiss Crans Montana resort has died, police said on Wednesday.

The man was a 34-year-old French citizen who worked for the local snow patrol and who was badly injured by the mass of snow that hit the piste the previous day, according to a tweet by the police department of the Valais region.

He and three slightly injured people were rescued on Tuesday.

The large search effort that involved some 250 rescue workers as well as a dozen sniffer dogs was called off on Wednesday morning as no additional buried skiers were found during the night.

The avalanche came down on Tuesday afternoon, piling several metres of snow onto a 400-metre stretch of a ski slope.

Avalanches hit secured slopes only very rarely in Switzerland. Prior to this week's fatality, only one person had died in such an incident in the past decade, according to the national snow research institute SLF.

In contrast, more than 220 people who skied in open terrain were killed by avalanches in the past 10 years.

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