Rescuers found the unnamed woman trapped under snow Wednesday and seriously injured after she was carried by a sheet of snow 100 meters (328 feet) wide and 250 meters (820 feet) long that detached from the slope. She died at a Sion, Switzerland, hospital after she was transported by helicopter, the Swedish news website The Local.se reported Thursday.
Her three skiing colleagues escaped injury. The group was skiing off-piste, on fresh snow not yet compacted into tracks, the website said.
With milder weather conditions following two days of heavy snow, police had issued a regional avalanche warning, and Eric Belet, director of the ski resort, told the Swiss newspaper 20 Minutes explosives had been used Wednesday morning to make high-risk ski areas safer.