For weeks the weight had sat above the village,nine million tonnes of rockprecariously resting on an ancient slab of ice. A chunk of Kleines Nesthorn mountain’s peak had crumbled, and its rubble hung over the silent, empty streets of Blatten, held back only by the glacier. The ice groaned beneath the pressure.
On Wednesday afternoon, in an instant,it gave way. The ice cracked, then crumbled. The entire mass descended into the valley below, obliterating the village that had been there for more than 800 years.
“Blatten has been wiped away. Erased, obliterated, destroyed, stamped into the ground,” the village’s mayor, Matthias Bellwald, said on Friday. “The memories preserved in countless books, photo albums, documentation – everything is gone. In short, this is ground zero for Blatten.”
Looking down from the slope above where the village once lay, you can still see the peaks of a few houses, piercing the mud. The valley is a lush sweep of green, pricked with wildflowers that have thrived on Switzerland’sunusually long, warm spring. But its pasture is now bisected by an enormous brown-grey mass of dirt, ice and rock, dozens of metres thick and about two kilometres long. The avalanche hit the valley with such force it has washed up the other side like a wave in a bathtub.
Almost all of the 300 residents had been evacuated a week earlier after authorities grew concerned about the stability of the mountain. One 64-year-old man, believed to have stayed in the area, is missing. As Blatten’s people shelter in the adjacent villages, gratitude for having escaped alive is mixed with grief at the enormous loss: of homes, businesses, history. “The people have lost everything, except for what they are currently carrying on their bodies,” Bellwald said. “Houses, bridges, real estate – they no longer exist.”
The scale of the glacial landslide that hit Blatten is near unprecedented in the Swiss Alps. But glaciers and permafrost are melting and destabilising across the world. As they do, terrain that was once frozen solid iscrumbling and sinking. Some glacial lakes are overflowing, and rivers of ice that have endured for millions of years are cracking, shrinking and being loaded with debris. How these mixed structures of earth and ice will behave in a rapidly warming world is unpredictable. Those that collapse can send great waves of water, rock and ice downhill, obliterating everything in their path.
“What you’re seeing is [happening] all over the world,” said Jan Beutel, a computer engineering scientist who specialises in seismic monitoring of mountain systems, as well as a mountaineer who knows the slopes surrounding Blatten well. He had been keeping a loose eye on the Birch glacier for weeks, and had a live stream running in the background as he worked on Wednesday – listening to its cracks and grumbles.
As the noise grew, Beutel watched the collapse in real time. “Suddenly, I saw the pixels exploding in the top half of the screen. I was just in awe,” he said. The impact was akin to a bomb going off. As the lens was obscured by the dust cloud, he searched for seismic data to estimate the size of the rockfall – and found it had registered as a 3.1 magnitude earthquake, one of the largest mass movements of earth ever recorded by the Swiss Seismological Service.
“For sure, there will be more. There will be harm to infrastructure, to livelihood, to interests,” he says. “The same thing is taking place in all mountain areas. The glaciated areas are going back. The sustained snow cover is less over the years, and permafrost is warming at a global scale.”
Stéphane Genoud, who lives in Anniviers, a short distance from Blatten, spoke during a pause between working to clear his property of broken trees – their trunks cracked by a year of unusual, sporadic dumps of snow. The Blatten disaster is only the latest and most dramatic of the changes that have transformed these valleys over his lifetime. “The change is very rapid,” he says. “We have less and less snow, the glaciers are all retreating, the ice that solidifies the rock is melting. There are routes in the high mountains that are no longer accessible.”
“An entire village disappearing under ice and rock is obviously not normal,” Genoud says. “Imagine your village disappearing, under meters of scree. There is no village. In two minutes: the village is gone.”
But he believes the collapse is part of a far larger disintegration, as global heating accelerates. “Now, with climate change, the mountain is coming down,” he says. “We are the canary in the coalmine – we are directly feeling the impact.”
Even for those who spend their careers monitoring glaciers and their retreat, these sudden, catastrophic collapses are shocking. “I’ve been astonished by the large-scale collapse and detachment of glaciers that has occurred in different parts of the world in recent years,” says Andrew Mackintosh, a glaciologist and professor of earth science at Monash University in Melbourne. “This is not something that I anticipated, particularly situations where entire glaciers detach and then fall into the valleys below.”
Often, the people living beneath were not as lucky as those in Blatten, which was almost completely evacuated before the collapse. During the 2002 Kolka-Karmadon glacier collapse in the Russian Caucasus mountains, more than100 million cubic metresof ice and rock plummeted into the valley, depositing debris 130 metres thick. It completely buried the village of Nizhniy Karmadon,killing at least 120people. In Italy, 11 died in the collapse of part of the Marmolada glacier in 2022. In Kyrgyzstan that same year, a group of British tourists were engulfed –but survived– an avalanche caused by the collapse of a glacier in the Tian Shan mountains.
ForSwitzerland– a country used to managing significant natural hazards from its mountains – the devastation of Blatten represents a new kind of destruction. When the Swiss president, Karin Keller-Sutter, returned from a helicopter flight over the damage on Friday afternoon, she said the sight was “apocalyptic”.
“It’s practically levelled. There have always been landslides. But with those, something always remained. Here, nothing is visible any more.”
Precisely attributing the Birch glacial collapse to climate change is not yet possible: even attribution studies for extreme weather take weeks or months, and landslides add an additional, complex set of factors to analyse. A recentreview of 45 studiesof landslides in the alps found a clear link between the heating climate and increased smaller rockfalls or landslides – but for huge rock avalanches, there was not enough data to conclusively say. Exact attribution is almost beside the point, however, says Mackintosh: the climate crisis is already clearly destabilising alpine environments, and transforming entire ecosystems.
“The melting of mountain permafrost – frozen ground that literally glues together the high alpine summits – leads to unstable situations where whole mountain slopes can collapse under their own weight,” sayssaid Mackintosh. In temperate glaciers, this can create a kind of feedback loop: the blanket of rock that coated Birch glacier speeded its melting. “These processes lead to a condition where a catastrophic landslide of rock, ice and snow is possible, with devastating consequences.”
From the hiking tracks that twine around the mountain above Blatten, the scale of that devastation is clear. Other than a few crested rooftops, nothing remains. The valley is mostly silent, broken by birdsong and the growl of a helicopter above the debris, watching for any movement. Authorities say there is no timescale for accessing the site: it is still too unstable. The sea of rock that covers it is threaded by tracks of water. When the landslide hit, it dammed the Lonza River, which ran through the valley, and regional authorities feared “a torrential lava flow if the river overflows”. Now the water has begun to eat its way through. In Kippel, which lies just a few minutes drive from Blatten, locals gathered to watch the new flow of brown, roiling water wind through the valley below.
None of Blatten’s evacuees, other than town officials, have yet spoken publicly about the loss of their town. “You can imagine, this was a very quiet, closed, introverted place even before,” says Brigitte Burgisser, who manages a meditation centre in neighbouring Kippel. “Now, there is such grief as well.”
The tiny, tight-knit community that lived here hope to rebuild. The valley without Blatten is “unthinkable,” says the mayor, Bellwald. But where or when they can do so is not clear.
For now, the only version of Blatten village that exists is invisible, Bellwald says, held in the minds of the people that have left. “We carry that with us very carefully, as a memory.”