Nepal flash floods: Avalanche at mountain in Nepal occurred after glacier broke away

On August 26, 2026, flash floods and mudslides swept through mountainous regions along the Nepal-Tibet border, resulting in at least 177 deaths, with the death toll expected to rise. Nearly 1,500 people are missing across the region, including around 600 foreign tourists in Nepal. The deluge, consisting of mud and rocks, swept through the Lhende Khola river valley, washing away at least 19 bridges and approximately 40km of roads, along with numerous homes and critical infrastructure. No rain was present, and there were no warnings issued.

Satellite images revealed that an avalanche occurred at the north face of Mount Langtang Lirung around 8:37am Nepal time, coinciding with a 4.4-magnitude earthquake near the China border. The glacier on Mount Langtang Lirung, which stands at 7,245m, lost a significant portion at an elevation of about 5,200m. This massive chunk of ice plunged approximately 1,200m onto the valley floor, gathering rock and sediment as it fell.

The debris flow blocked the Lhende Khola, a Himalayan river originating in Tibet that flows into Nepal. The river, already swollen due to the monsoon season, burst soon after, sending a wall of mud and boulders racing down the Trishuli River, causing water levels to rise by up to 9 meters within 30 minutes.

Initially, experts believed the earthquake caused the slope collapse, but the United States Geological Survey later determined that the seismic signal was generated by the landslide itself. The landslide eventually registered as a magnitude 5.2 seismic event. The worst damage occurred in Nepal’s Rasuwa district, situated immediately south of the Chinese border.

It remains too early to determine the exact cause of this specific event, but researchers are investigating whether melting glaciers contributed to the instability of the mountain slopes.