On Wednesday afternoon, a wall of water surged down the river valleys that straddle the Nepal-Tibet border, moving fast enough to overturn trucks, swallow power stations and level entire villages before most residents had any chance to reach higher ground. By Thursday morning, at least 356 people had been confirmed dead, while rescue teams were still searching for nearly 1,400 others — the majority of them tourists from India, the United States, the United Kingdom, Australia and Canada who had come to trek or make religious pilgrimages in one of the world's most dramatic mountain landscapes. The scale of the destruction has made the search operation extraordinarily difficult. Approximately 40 kilometres of road have been obliterated and dozens of bridges destroyed, cutting off the affected districts of Nuwakot and Dhading from the outside world.

The Nepali army had airlifted more than 100 survivors by helicopter by Thursday morning, and dozens of injured people had been transported to Kathmandu for specialist medical care. Bodies were recovered as far as Chitwan district, hundreds of kilometres downstream, indicating how far and how forcefully the floodwaters travelled. David Fisher, head of the Nepal delegation of the International Federation of the Red Cross, confirmed that entire villages and market areas had been wiped out. Among them was Soley, in Nuwakot, a settlement of roughly 25 homes that is reported to have been almost completely destroyed.

Kathmandu-based journalist Nirajan Paudyal travelled to the area on Thursday to find his own family, who live there. He had received no news of them. "I fear there won't be any update," he said. Across the border in Tibet, Chinese officials warned of "major casualties" after a mudslide struck a key border crossing.