The Alpine village of Blatten in Lotschental valley in southern Switzerland was buried under large volumes of ice and rock debris May 28, 2025 as a massive chunk of the Birch glacier broke off and slid down the mountian slope.
An elderly man is reported to be missing. The around 300 residents of the village, who were evacuated earlier in the month, lost their homes and everything that belonged to them. As much as 90 per cent of Blatten was destroyed and the area is now under a thick layer of sludge, the security head of the affected region told local news channels.
The region is now at risk of flooding as debris have deposited on River Lonza flowing in the vicinity, blocking off a part of the waterbody. The lake that has formed as a result is filling up at rapidly, raising concerns of flooding if the morane banks give away.
People from neighbouring villages are being evacuated in view of such a disaster. Helicopters have been deployed to assess the extent of damage, the local authority informed.
Glaciers over an extensive area in Switzerland are retreating due to global warming. Around two weeks ago, scientists reported a massive rock instability over Birch glacier. Rocks of various sizes were observed to be breaking off the mountain above and tumbling onto the glacier, causing it to begin to move.
The loosening of the rocks from the mountain, according to some glaciologists, could have been due to the thawing of the permafrost because of global warming.
On May 19, when the glacier movement reached a critical level and the risk of a landslide on Blatten became apparent, the villagers were evacuated along with their livestock.
Physical geographer and remote sensing specialist Mylene Jacquemart told the news agency Reuters that it is unclear whether the disaster can be attributed to climate change, but rising temperatures have made high altitude landscapes more unstable. More water availability due to ice and snowmelt and higher rainfall, rather than snowfall, may be a factor inducing this, she said.
Water percolacing between rocks and in the soil reduces cohesion, increases weight, enhances weathering and accelerates erosion. These, in turn, can cause them to break off and slide down.
The crisis is far from over for the region. By May 29, debris from the mudslide has formed a 2km long wall across the bed of River Lonza, abruptly blocking its flow. Behind this, a large volume of water from the river has accumulated and this lake is swelling at a rate of 80 centimetres an hour, according to local authorities. If the debris blocking the river gives away, the sudden gush of water from the river and melting glacier chunks could flood the entire Lonza valley, fear experts.
People living in Gampel and Steg villages along Lonza are also preparing to evacuate. "The army is standing by with water pumps, diggers and other heavy equipment to provide relief when conditions allow," Reuters reported.
Blatten isn't the first village in Switzerland to face such a tragedy in recent years. The residents of Brienz in the eastern part of the country were evacuated twice, in 2023 and 2024, for similar concerns. In 2023, some 1.2 million cubic metres of a rock rolled down the slope towards Brienz and narrowly missed the village.