Deadly Floods Sweep Through Nepal, Killing More Than 350, Over 1000 Still Missing

On Aug. 23, catastrophic flash floods tore through communities along the Nepal-China border, claiming the lives of least 160 people and leaving hundreds missing after an enormous collapse of ice and rock high in the Himalayas sent a wall of water and debris rushing downstream.

By the evening of Aug. 27 local time, the death toll had risen to at least 350, according to a

At least 157 deaths had been confirmed in Nepal as of Aug. 26 (Wednesday), while three people were reported dead across the border in Tibet, according to the Associated Press (AP), as the death toll continues to climb. More than 800 people remained unaccounted for, including hundreds of foreign tourists visiting the mountainous region.

The disaster struck Nepal’s northern Rasuwa district around 9 a.m., when water levels along the Bhote Koshi River suddenly surged. Within minutes, the torrent swept downstream into the Trishuli River, carrying mud, rocks, and other debris as it devastated entire communities in its path.

Videos from the region showed residents running as a towering mass of muddy water engulfed buildings and vehicles within seconds. Helicopters were dispatched to rescue people stranded on rooftops as emergency crews searched devastated communities.

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A helicopter pilot who witnessed the flood from above estimated that waves reached roughly 5 to 6 meters, or 16 to 20 feet. “We could see water waves as high as five to six meters … We started circling around villages there and could see big trees along with a few vehicles being swept away,” pilot Aman Budathoki told CNN. “It was a very scary situation,” Budathoki added, “We even tried to chase the flood for a while just to assess the damage unfolding.”

Hundreds missing as rescue efforts ramp up

The sheer scale of the destruction is still unfolding. At least 19 bridges and nearly 40 kilometers, or about 25 miles, of roadway were swept away, according to AP. Hydropower facilities and villages along the Bhote Koshi were also severely damaged. Authorities warned residents in several districts to stay away from the Bhote Koshi, Trishuli and Narayani riverbanks amid fears of further flooding.

Among those missing were 826 tourists and pilgrims, including citizens of India, the United States, Australia, Britain, South Korea and several other countries. CNN reported that at least 47 Americans were among those unaccounted for, while Nepalese authorities said 28 police officers were also missing.

The U.S. State Department said it was aware of Americans affected by the disaster and was coordinating with Nepalese authorities and tourism agencies to assist in search and rescue efforts. “The United States stands ready to assist,” a department spokesperson said. Nepal also sought rescue assistance from neighboring India and China.

Across the border, Chinese authorities reported extensive damage around Gyirong in Tibet, where a mudslide disrupted roads, communications, and electricity. Chinese leader Xi Jinping ordered search-and-rescue operations as authorities reported 265 people missing on the Tibetan side.

Scientists examine what triggered the disaster

Initial accounts of the flood’s cause were conflicting. Nepalese officials initially said an earthquake had triggered a landslide that blocked the Bhote Koshi River before the natural dam collapsed, unleashing the torrent downstream. But scientists later pointed to a massive ice-rock avalanche or partial glacial collapse as the likely trigger.

Researchers with the International Centre for Integrated Mountain Development (ICIMOD) said preliminary evidence suggested a large volume of ice and rock entered the Lende Khola, a tributary of the Bhote Koshi, which generated the sudden and severe surge.

The flood’s speed was extraordinary. ICIMOD said the Trishuli River rose by as much as nine meters, nearly 30 feet, in just 30 minutes at one monitoring location. Scientists were also investigating whether debris temporarily dammed the river, raising concerns that another sudden release of water could occur.

A rapidly-changing Himalayan landscape

The disaster has again drawn attention to the vulnerability of Himalayan communities as rising temperatures transform the region’s glaciers, snowpack and mountain slopes. The Himalayas contain thousands of glaciers that feed rivers supporting communities across South and Central Asia. As temperatures rise, melting ice and destabilized mountain slopes can increase the risk of avalanches, landslides, and glacial lake outburst floods.

ICIMOD has previously warned that rising temperatures are accelerating glacier loss and contributing to growing cryosphere-related hazards, including permafrost and mountain stability changes, across the region. However, researchers are still investigating the precise chain of events behind the Aug. 23 flood.

“The increasing frequency of cryosphere hazards is becoming more visible than ever before,” ICIMOD senior cryosphere specialist Mohd. Farooq Azam said, adding that the pace of environmental change is becoming a growing challenge for preparedness and rescue efforts.

But for communities downstream, the immediate concern remains in the search for survivors. With hundreds still missing and unstable debris potentially threatening another surge, authorities warned that the full extent of the disaster may not yet be known for days or even weeks to come.