The US Geological Survey initially linked the flooding to a magnitude 4.4 earthquake recorded in the area
A massive glacier and rock collapse high in Nepal’s Himalayas appears to have set off a chain of events that culminated in one of the country’s deadliest flash floods in years, killing over 600 people and leaving thousands missing in Nepal and neighbouring Tibet. The USGS later revised its assessment, concluding that the collapse itself produced a seismic signal equivalent to a magnitude 5.2 earthquake. In Nepal’s Rasuwa district, soldiers were deployed to rescue people trapped inside a tunnel at the Upper Trishuli-1 hydropower project, where thick mud made it difficult to locate the entrances and exits. By Friday, Nepal’s disaster-management authority had reported 579 deaths, while Nepal Police put the toll at 553. More than 3,700 people had been rescued and 1,924 remained unaccounted for. China reported seven deaths and 554 missing. Chinese monitoring data later showed the lake’s water level had fallen by about 10 metres from its peak.
Bodies have been recovered hundreds of kilometres downstream in Nuwakot, Dhading, Chitwan, Gorkha, Tanahun and both East and West Nawalparasi, according to Nepal Police, tracing the path of the flood through the country’s major river systems. The scale of the destruction has since become clearer. The initial surge flattened settlements, roads, bridges and hydropower infrastructure on both sides of the border. The disaster also created a new danger. A lake formed upstream after the glacier collapse and began overflowing, prompting warnings that another surge could hit communities downstream. Rescue teams were temporarily ordered to stop advancing while authorities assessed the threat.