Natural disaster buries Swiss town and creates a new natural dam

BLATTEN – On May 28, 2025, the Swiss village of Blatten was struck by a catastrophic natural disaster when a massive section of the Birch Glacier collapsed into the valley below. Triggered by destabilizing rockfalls from the nearby Petit Nesthorn, the collapse unleashed millions of cubic meters of ice, rock, and debris, burying around 90% of the village and causing a 3.1-magnitude earthquake.

Fortunately, Blatten had been evacuated on May 19 after early signs of geological instability were detected. Thanks to these precautions, no fatalities have been reported, though one resident remains missing. In the aftermath, the debris blocked the Lonza River, forming a natural dam that now poses a serious flood risk to the surrounding area.

This event underscores the growing dangers posed by climate change in alpine regions. As glaciers melt and permafrost destabilizes, the risk of sudden, large-scale natural disasters is increasing for mountain communities.