More than 1,300 people are confirmed dead in Nepal and over 5,000 remain missing after the 26 August Langtang Lirung rock-ice avalanche turned into a debris flood; 13,700 were rescued and 8,600 treated.
Roughly 2 square kilometers of rock wall and glacier ice collapsed from about 5,150 meters, falling 1,400 meters and releasing energy equivalent to a magnitude-5.5 quake that was first mistaken for an earthquake.
A wall of water, ice, rock and sediment reached the Rasuwagadhi border 22 km downstream in seven minutes at an average 188 kph, then destroyed Timure, Syabrubesi and settlements farther down the Trishuli valley.
About 84,270 people across 17 local levels in six districts are affected, 3,400 are in holding centres, and Nepal has declared 15 municipalities disaster crisis-hit areas for three months.
Researchers say warming, permafrost degradation, glacier retreat and more rain than snow likely destabilized a geologically vulnerable slope, underscoring that Himalayan hazards are increasingly exceeding existing early-warning and adaptation limits.