Collapsing mountains: Where's next and how to avoid future disasters?

On May 28, 2025 at 3.30 PM, the village of Blatten (Switzerland) witnessed the most devastating and unprecedented rock-ice avalanche in the European Alps, destroying the homes of 300 residents. This recent disaster exemplifies the increasingly complex, cascading nature of emerging mountain hazards, where climate change, cryosphere degradation, and slope failures interact to produce mass movements of exceptional consequence. This recent calamity also provides insights into how such events could be managed in other mountain ranges in an increasingly warmer world. Mountain disasters will become increasingly unpredictable in a warmer world. This short communication therefore calls for improved process understanding, monitoring and risk management. • Rock ice avalanche at Blatten marks the largest alpine slope failure in decades. • Climate-driven cryosphere degradation fuels cascading rock-ice hazard chains. • Terrestrial and satellite monitoring enabled timely evacuation before collapse. • Blatten showcases need for global, integral risk management in high mountains.