A section of glacier broke away roughly 5,200 meters up in the Himalayas on Wednesday morning, plunging as an ice-and-rock avalanche into the Lhende River in Tibet's Gyirong County. The debris temporarily dammed the river; when the natural blockage gave way minutes later, it sent a wall of water, mud and boulders roaring downstream into Nepal's Rasuwa district and beyond. By Thursday morning, officials in Nepal and China put the confirmed death toll at more than 270, with nearly 1,500 people still missing across the border region.
Rasuwa bore the worst of the damage before floodwaters spread into the neighboring Nuwakot and Dhading districts. Nepal's disaster authorities said 826 people remain missing in the country alone, including roughly 600 foreign nationals from more than two dozen countries who were trekking or traveling in the area when the flood hit. At least 19 bridges and 40 kilometers of roads were destroyed, along with hydropower infrastructure including the Rasuwagadhi, Chilime, Trishuli and Devighat stations, according to reporting compiled by Al Jazeera. Three deaths and hundreds more missing were reported on the Tibetan side of the border.
Among the missing are at least 34 Australians, including 15 trekkers on a US-run Himalayan Glacier Adventures tour that had set out from Kathmandu days earlier on a planned 13-day trek toward the sacred Mount Kailash and Lake Manasarovar on the Tibetan Plateau, according to ABC News Australia. American tourists are also among those unaccounted for, and Nepal's tourism board says citizens of more than 30 nations were registered on trekking permits in the affected valleys this week.
What triggered the collapse
The US Geological Survey initially recorded a seismic signal consistent with a magnitude 4.4 earthquake near the Nepal-China border around the time the flood began, but revised its assessment after review, concluding the shaking was generated by the landslide itself — releasing energy roughly equivalent to a magnitude 5.2 quake — rather than by tectonic movement. Satellite imagery reviewed by scientists showed the glacier fracture and subsequent debris dam formed and failed within a short window Wednesday morning local time, a pattern consistent with a glacial-outburst-style event rather than a conventional flood.
Scientists caution that a full attribution study will take time, but the region's glaciers have been retreating at an accelerating pace. A landmark assessment from the International Centre for Integrated Mountain Development found that Hindu Kush Himalayan glaciers lost ice 65% faster between 2011 and 2020 than in the preceding decade, leaving increasingly unstable ice and debris dams above valleys that are home to millions of people and, in peak trekking season, thousands of foreign visitors.
Rescue effort and reaction
More than 5,000 Nepalese army and police personnel have been mobilized, working with helicopters, drones and search dogs to reach communities where roads have been washed out entirely. Officials say some of the worst-hit settlements can only be reached by air, and that even helicopter landings are difficult given the steep, unstable terrain left behind by the flood. The United Nations has deployed personnel to support the relief effort, and Nepal has received additional aid pledges from India, South Korea and the United States.
There is devastation everywhere we look.
Tula Bahadur BK, health worker in Rasuwa district, via Reuters
A local teacher who witnessed the flood described trucks and people being swept away in the initial surge. "I saw around nine trucks being swept away by the floods, including people. It's a heartbreaking incident," the teacher said, according to accounts gathered by Al Jazeera. Officials have warned that the confirmed death toll is likely to rise further as rescue teams reach areas that remain cut off.
Search operations are expected to continue for days, with priority given to reaching isolated villages and identifying the trekking groups still unaccounted for on both the Nepali and Tibetan sides of the border. Governments including Australia and the United States have activated consular response teams to work with Nepali authorities as families wait for word on missing relatives.
