When a mountain falls: How ice and rock triggered Nepal’s catastrophic flood – and why climate change is raising the risks

On August 26, 2026, a catastrophic flood in Nepal killed hundreds of people and left many more missing.

The disaster began when a massive amount of bedrock and glacier ice broke off a mountainside near Langtang Lirung, approximately 4,000 feet (1,200 meters) above a valley.

This collapse generated a landslide that registered as a magnitude 5.2 earthquake on seismometers.

The landslide created a slurry of melting ice, rock, and water that flowed into a nearby river, destroying infrastructure and taking lives.

Days later, a new barrier lake formed behind the debris, which then burst, sending another wave of water downstream.

The flood disrupted multiple hydropower plants, destroyed bridges, and damaged a major trade route between Nepal and China.

Rescue operations were complicated by the ongoing threat of further flooding.