Three of them died from hypothermia while the fourth is believed to have died in a fall, police in the canton of Valais said.
Police in Valais in southwestern Switzerland said seven helicopters were used to rescue 14 people in the Pigne d'Arolla region early on Monday.
https://news.sky.com/story/four-skiers-die-in-swiss-alps-after-spending-night-outdoors-11353989