Nepal flash flood kills at least 157 as ice avalanche triggers river surge

Disaster along the Himalayan border

A flash flood swept through the Nepal-Tibet border region on Wednesday, leaving at least 157 people dead in Nepal and three in the Tibetan district of Gyirong. Nepali police confirmed that 403 people remain missing on the southern side of the frontier, while Chinese authorities reported 265 people unaccounted for in Gyirong. Floodwaters surged along the Bhote Koshi and Trishuli river valleys, catching residents and travelers with little warning early in the morning. Local residents described hearing a continuous roar before muddy torrents inundated riverbank communities and submerged lower floors of buildings. Sonam Dorjee, a tour guide based in the Rasuwa village of Syapru Besi, narrowly escaped when he departed early for an excursion.

It sounded like an earthquake.

Widespread destruction in Rasuwa district

The flood destroyed basic infrastructure across Rasuwa district, home to approximately 50,000 residents, with the settlements of Syapru Besi and Timure suffering the heaviest impact. Rushing debris leveled several villages, damaged hydroelectric power plants, disrupted regional electricity grids, and severed nearly 40 kilometers of roads. Narendra Pariyar, the chief administrator of Rasuwa district, reported that entire riverside settlements were flattened by the surge. Water resources officials confirmed that at least 19 bridges were torn down along the river corridor, cutting off ground transit. Health worker Tula Bahadur BK described losing multiple relatives as settlements disappeared in the torrent.

Everywhere we look, there is destruction. Settlements along the river were completely wiped off the face of the earth. Five of my relatives are missing.

Foreign pilgrims and tourists missing

The disaster caught hundreds of travelers in a popular corridor for trekking, rafting, and religious pilgrimage. Nepali tourism officials stated that 341 of the 403 missing individuals in Nepal are foreign nationals. Among those unaccounted for are 133 Indian pilgrims traveling toward Mount Kailash in Tibet, 47 citizens from the United States, 34 from Australia, 33 from the United Kingdom, 24 from Canada, and eight from South Korea. Prime Minister Balendra Shah deployed Nepali military and police search-and-rescue units to evacuate threatened areas and assist survivors. Across the border, Chinese leader Xi Jinping ordered search efforts and called for strengthened disaster-monitoring systems.

Avalanche trigger and continuing hazards

Initial government statements, including remarks by Nepal Foreign Minister Shisir Khanal, attributed the catastrophe to a magnitude 4.4 earthquake. The United States Geological Survey later revised this assessment, concluding that the recorded seismic vibrations were produced by a massive landslide rather than tectonic fault movement. Satellite imagery analyzed by meteorological authorities indicated that a large mass of glacial ice and rock broke away northeast of the Rasuwa Gadhi border crossing, dumping debris into the Lhende river and forming a temporary dam. Professor Liz Stephens of the University of Reading noted that high-altitude floods frequently stem from complex interactions rather than rain alone.

Most people think flash floods are caused by heavy rainfall, but in Nepal and Tibet, as in many other high mountain regions, they can also be the result of a complex cascade of hazards.

Downstream communities remain under evacuation orders along the Bhote Koshi and Trishuli rivers because residual debris dams in the upper river basin could release additional flood waves.