A catastrophic glacier collapse in the Swiss Alps sent millions of cubic meters of debris crashing down into the valley above the village of Blatten, Switzerland, on Wednesday, May 28, triggering a massive mudslide that buried large parts of the Lonza riverbed and devastated the surrounding landscape.
The disaster, which authorities called a “worst-case scenario,” occurred after weeks of monitoring increasingly unstable conditions on the Birch Glacier. On May 19, officials had preemptively evacuated around 300 residents from the village amid signs of accelerated movement on the mountain. In a press release issued by the Commune of Lötschental, the Valais/Wallis State Council elaborated on its decision to declare a “special situation”—an emergency status that enables rapid mobilization of operational resources.
The declaration was made in anticipation of a major collapse from the Birch Glacier, which, officials warned, was under extreme pressure from recent rockfalls on the adjacent Kleiner Nesthorn. These rockfalls, involving millions of cubic meters of material, exerted immense force on the glacier, accelerating its movement toward the valley and dramatically increasing the risk of catastrophic landslides or mudflows. Despite these precautions, the sheer scale of Wednesday’s collapse—involving approximately three million cubic meters of ice, rock, and mud—stunned local authorities and residents alike. It is estimated that approximately 90% of the village was destroyed by the ice, rock, and landslide.
Drone footage released by emergency responders shows the valley floor buried under debris up to 200 meters deep in some places. The full extent of structural damage remains unclear, but officials confirmed that large swaths of the village were affected. “The incomprehensible has happened,” Matthias Bellwald said, mayor of Blatten, during an emotional press conference. “We have lost the village today, but not the heart. The mountain and the glacier cannot come down twice. We help each other and comfort each other.” Houses that escaped the landslide are now being flooded by the Lonza river as the river’s natural run is blocked by the landslide. Neighboring villages Wiler and Kippel have announced evacuation zones for houses close to the Lonza river as the river is swelling and spilling over the banks.
So far, there have been no reports of injuries, but one person is missing, the municipality confirmed late Wednesday. The missing person was identified by the cantonal police of Valais/Wallis as a 64-year-old local man. Rescue and recovery efforts remain underway amid treacherous conditions. Authorities urge the public to strictly comply with all safety instructions and avoid the hazard zone. The cantonal leadership body—in collaboration with civil protection units and, if necessary, the army—continues to monitor the situation closely. Officials emphasize that although much of the glacier has now collapsed, ongoing surveillance and caution remain vital. The terrain remains unstable, and further slides cannot yet be ruled out.
Emergency services have been reinforced by military units and civil defense teams. Pumps and heavy equipment were airlifted into the valley to clear debris and stabilize the riverbed. Lighting systems have been installed to support around-the-clock operations. The canton of Valais/Wallis declared a “special situation” early Wednesday morning to coordinate the large-scale disaster response.
Before the collapse, experts from the Department for Natural Hazards had tracked roughly nine million tons of unstable material on the glacier. Authorities now believe most of that mass has come down. “We need to assess what’s still up there,” a department spokesperson said. “But the primary threat has been realized.”
As the shock settles, Blatten—nestled in the Lötschental, one of Switzerland’s most scenic alpine valleys—faces an uncertain future. For now, residents are united in grief and resilience. “The village may be gone,” Mayor Bellwald said, “but our community endures.”
