GENEVA (AP) — A 64-year-old man remained missing Thursday after a huge mass of rock and ice from a glacier crashed down a Swiss mountainside the day before.

The landslide sent plumes of dust skyward and coated with mud nearly all of an Alpine village that authorities had evacuated earlier this month as a precaution. State Councilor Stéphane Ganzer told Radio Télévision Suisse that 90% of the village was destroyed.

The Cantonal Police of Valais said that a search and rescue operation was underway for the man, whose name wasn't made public, and it involved a drone with a thermal camera.

The regional government said in a statement that a large chunk of the Birch Glacier above the village had broken off, causing the landslide, which also buried the nearby Lonza River bed, raising the possibility of dammed water flows.

Video on social media and Swiss television showed that the mudslide near Blatten, in the southern Lötschental valley, partially submerged homes and other buildings under a mass of brownish sludge.

In recent days, authorities had ordered the evacuation of about 300 people, as well as all livestock, from the village amid fears that the 1.5 million-cubic meter (52 million-cubic foot) glacier was at risk of collapse.

Swiss glaciologists have repeatedly expressed concerns about a thaw in recent years — attributed in large part to global warming — that has accelerated the retreat of glaciers in Switzerland.

The landlocked Alpine country has the most glaciers of any country in Europe, and saw 4% of its total glacier volume disappear in 2023. That was the second-biggest decline in a single year after a 6% drop in 2022.