Volkswacht Bodensee - Swiss glacier collapse could cost huge sums: insurers

This is a "major disaster that is virtually unprecedented in its scale and impact on the affected population", the SIA industry body said in a statement.

It is not yet possible to give a "precise estimate of the extent of the damage", it said.

However, Eduard Held, the association's specialist in damage caused by natural hazards, expects "a loss of several hundred million francs (dollars)", the statement said.

On Wednesday, the Birch glacier collapsed, sending scree, ice and mud hurtling down into the Lotschental valley in Switzerland's southern Wallis region.

The disaster destroyed most of Blatten, which had been home to 300 people and was evacuated the week before due to the impending danger.

Houses which escaped the landslide have become submerged in an artificial lake as the two-kilometre-long barricade of debris blocks the river Lonza in the valley floor.

- Missing person search resumed -

"Our first thought is the victims who are currently in a very difficult situation. Private insurers are striving to provide them with assistance as best they can and without unnecessary formalities," said Held.

The Birch glacier was below the 3,342-metre (10,965-foot) high Kleines Nesthorn peak.

In the fortnight before the glacier's collapse, a series of falls from the mountain dumped three million cubic metres of rock onto the ice surface.

That increased the weight, and with the glacier on a steep slope, it ultimately gave way in dramatic fashion, plunging down on Blatten in the valley.

Experts said it was too early to make a direct link to climate change, but told AFP that thawing permafrost in the cracks in the rock likely played a role in destabilising the mountain.

A 64-year-old man, believed to have been in the danger zone at the time, remains missing.

The search resumed in a demarcated area on Monday, with mountain specialists and dog handlers airlifted to the scene. A mechanical excavator has also been deployed.

- Early warnings -

Speaking at a conference in Geneva, Celeste Saulo, the head of the World Meteorological Organization -- the United Nations' weather, climate and water agency -- called the disaster "a potent warning about our warming world".

"But behind the shock, it's a message of hope," she added.

"Early action avoided human losses. From understanding risk to effective forecasts, communication and evacuation, early warnings and early action work. They save lives."

Maarten van Aalst, the director-general of the Royal Netherlands Meteorological Institute, said Blatten "reminded us that we need the early warning systems even more in a changing climate".

"Even in the best-prepared countries there is still work to do and there's new threats to counter in this day and age and that early warnings play a critical role," he said.

D.Bachmann--VB