Catastrophic flooding triggered by a glacial collapse and debris flow along the Nepal-Tibet border has left at least 160 people dead and hundreds missing. The disaster swept away bridges, collapsed multi-storey buildings, and disrupted major transport routes north-west of Kathmandu.
Glacial Collapse and Debris Flow Displace Rivers
The disaster unfolded on the morning of Wednesday, August 26, 2026, when torrents of water and debris crashed downstream on both sides of the border between Nepal and Tibet. While the US Geological Survey had first reported the event as a magnitude 4.4 earthquake on Wednesday, it said on Thursday that analysis had confirmed that "no earthquake had occurred" and that the disaster "was instead a glacial collapse and debris flow" that "caused subsequent catastrophic impacts downstream." Surveillance video from the Chinese side showed a wall of mud and water crashing over a building as terrified people ran away, while a surge of water hit villages and towns on the path of two rivers in Nepal: the Bhote Koshi and the Trishuli.
According to Nepal’s National Disaster Risk Reduction and Management Authority, citing a preliminary analysis of Planet Labs satellite imagery, a rock-and-ice landslide along the Nepal-China border, about 20 km northeast of the Rasuwagadhi border crossing, caused a debris-laden flood in the Lhende River, a tributary of Bhotekoshi, that flowed through Timure and entered the Trishuli River. The disaster was initially described as a flood on the Nepalese side, and a mudslide by Chinese authorities. While preliminary satellite analysis points to a rock-and-ice landslide as the immediate cause, experts say a thorough assessment is needed to establish the sequence of events and whether a glacial process also contributed to the flood.
Destruction in Trishuli Bazaar and Downstream Areas
Verified videos from Nepal show a bridge being swept away and multi-storey buildings collapsed by the force of floodwaters, as well as a town with many buildings destroyed. BBC Verify has located the clips to the town of Trishuli Bazaar area of Nuwakot District in Bagmati Province, about 25km (16 miles) to the north-west of Kathmandu. The video shows the river Trishuli suddenly becoming swollen by enormous amounts of water, which appears to have significantly increased in volume and speed and filled with sediment. About 40 seconds into the clip, the weight of the flash flood rips the bridge off of its supports and carries it swiftly downriver. A few seconds later, several buildings also collapse. A second verified video, filmed from the same location, shows the devastating aftermath, where the river's level has risen significantly and trees and many buildings visible in the earlier video have been ripped away.
A new video filmed from inside a bus in Trishuli shows dozens of people trying to flee as a flash flood surges down the valley. The verified video shows floodwaters rapidly swelling and spilling down the river, as many attempt to flee on foot, moped and other vehicles. Passengers can be heard crying out in alarm on board, as the bus drives along the road which follows the river. It is not clear exactly how many have been destroyed, but many buildings near the riverbank have disappeared, partially collapsed or are caked in sediment from the flood's force.
Official Statements and Secondary Flooding Warnings
Earlier, Foreign Minister Shishir Khanal told Parliament that preliminary information suggested an earthquake around 8.37 a.m. triggered an ice avalanche, which was followed by the flood around 8.40 a.m. "The information needed further verification," he said. Amidst the chaos, individual survival stories unfolded, including that of eight-year-old Zoyal Ghale. When the flood struck, Zoyal was inside his school classroom when darkness suddenly descended, and he and another individual managed to escape the school and run toward the jungle, where Zoyal climbed a tree to save himself from the rushing waters.
Several areas downstream of the Bhote Koshi river, which flows from Tibet to Nepal, are on high alert, and roads, communications, and power in the region have been disrupted, with authorities confirming that the main road to Kathmandu is closed. The International Centre for Integrated Mountain Development (ICIMOD) warned of a secondary potential flooding event as a result of the debris that washed into the river systems.
Infrastructure Pressures and Future Risks
The recurrence of extreme floods has raised concerns among experts about disaster preparedness, infrastructure planning, and risk mitigation. A construction spree along rivers in Nepal’s northern regions, driven in part by the country’s push to expand hydropower as an economic booster, has remained a concern for environmentalists and climate experts.
