On Wednesday morning, a wall of mud, rocks and water surged down the Trishuli River valley and consumed Bidur, the capital of Nepal's Nuwakot district. Within hours, most homes had vanished. The mangled concrete shells of a bank, a government office and an ATM booth were among the few structures still standing, though all were buried to their windows in grey silt. Survivors described clinging to trees and rooftops as the current swept over them.

Officials confirmed that bodies remained inside several buildings but said conditions were too dangerous to recover them. By Friday, the disaster had grown more complicated. A lake formed by debris from the original mudslide began overflowing near the Nepal-Tibet border, sending a fresh surge downstream and forcing rescue teams to withdraw from the search area. Residents of Rasuwa district — the mountainous border zone that links Kathmandu with Lhasa along a road popular with trekkers and pilgrims — were filmed sprinting up hillsides to escape the rising water.

Operations resumed only after the immediate threat had passed, though the risk of further overflow remained. The combined toll, as reported by Nepali and Chinese authorities, stood at at least 543 dead and more than 1,300 missing across both sides of the border. Nepal alone reported 826 people unaccounted for, of whom more than 500 held foreign passports: 177 from India, 90 from the United States, 34 from Australia, 33 from Britain and 25 from Canada. Chinese state media added that at least 558 were missing on the Tibetan side, including roughly 260 foreign nationals.