Rescue workers say they have given up hope of finding three people, missing since a landslide destroyed two chalets near Nendaz in canton Valais late on Tuesday. Police said the mudslide was triggered by a burst water main.
The victims disappeared after an avalanche of mud and rock swept 1,000 metres down into a valley, wiping out two chalets and a number of farm buildings.
"We are still hoping to find their remains," said the leader of the rescue mission, Paul-Andre Gillioz.
The three - a man and two women - were aged between 30 and 50 years old, and were walking their dogs when the landslide struck.
Police said a sudden escape of water from a pressurised pipe underground had destabilised an "enormous" amount of earth, causing the landslide.
The pipe leads to a nearby hydroelectric power plant, run by the Energie Ouest Suisse company. The production director, Pierre Desponds, said mountain guides had found a nine-metre crack in the pipe.
He said it was too early to say what had caused the pipe to burst.
The incident comes two months after a landslide swept through the mountain village of Gondo in canton Valais, killing 13 people. That disaster was set off by days of intense rain.
swissinfo with agencies