Overview
- A massive rock-and-ice collapse on Langtang Lirung triggered a fast debris and water flow that devastated downstream villages after the mountain flank failed on August 26, 2026.
- A mid-September analysis by World Weather Attribution concluded that human-caused warming materially increased the probability and severity of the chain of failures while noting it did not perform the detailed counterfactual needed to prove the event could not have occurred without warming.
- The report identifies interacting physical drivers that weakened the slope, including long-term glacier retreat, thawing high-altitude permafrost, large inputs of meltwater that raised pore pressure in rock, and record heat in the months before the collapse.
- The disaster left roughly 1,300–1,400 confirmed dead and more than 5,000 missing, destroyed roads, bridges and hydropower facilities, and has prompted ongoing rescue, drone relief and appeals from Nepal for billions in recovery aid.
- Scientists say the findings expand what monitors must watch for in high mountains, warn that local early-warning systems have physical limits, and note a 2015 magnitude-7.8 quake may have pre-weakened the slope but its exact role remains unclear.