The collapse of a Swiss glacier last week destroyed most of Blatten, a tiny village in Switzerland's southern Valais region that was home to about 300 people.
Footage of the May 28 collapse showed thousands of tonnes of ice and rubble hurtling down the mountainside into Blatten. The village was evacuated in the days before.
Celeste Saulo, secretary general of the World Meteorological Organisation, said at a conference in Geneva that the disaster was "a potent warning about our warming world".
"Early action avoided human losses," she said. "From understanding risk to effective forecasts, communication and evacuation, early warnings and early action work. They save lives."
The disaster is expected to cost hundreds of millions of dollars, the Swiss Insurance Association said on Monday.
The collapse was a "major disaster that is virtually unprecedented in its scale and impact on the affected population", it said in a statement.
