Overview

• An estimated 4 to 6 million cubic meters of ice, rock and sediment broke from Kleins Nesthorn’s Birchgletscher on May 28, burying 90% of Blatten’s buildings.
• Authorities evacuated Blatten’s 300 residents on May 19 after warning signs of instability, limiting human losses to one person still reported missing.
• Debris has blocked the Lonza river, causing waters to rise up to three meters per hour and forming a temporary lake behind the natural dam.
• Swiss Army engineers and rescue teams have evacuated 16 people from Ferden, Steg-Hohtenn and Gampel-Bratsch and drained a downstream basin to manage potential overflow.
• Geologists link the collapse to accelerated glacier melt and permafrost thaw driven by climate change, highlighting the need for expanded monitoring of alpine slopes.