A catastrophic flash flood triggered by a massive collapse of ice, rock and mud high in the Himalayas has killed more than 270 people across Nepal and China’s Tibet region, while more than 1,300 people remain missing as rescue crews race through devastated valleys and river corridors.

The disaster struck Wednesday along the Nepal-Tibet border and sent a violent surge downstream through the Lhende River system toward the Bhote Koshi and Trishuli rivers. Communities in Nepal’s Rasuwa, Nuwakot and surrounding districts were hit, while Gyirong County and its border port in Tibet also suffered severe destruction.

The latest figures remain fluid. The Associated Press reported at least 270 deaths in Nepal and three in Tibet, with 826 people missing in Nepal and 558 missing in Tibet. Reuters reported Nepalese police expected the death toll to rise beyond 270 as bodies continued to be recovered far downstream. Authorities have cautioned that missing-person lists are changing as survivors are located and communications are restored.

Security-camera footage shows a fast-moving surge of mud, rock and water overtaking buildings and vehicles in a developed mountain area.

Source: Chinese television/security-camera footage visible in the clip; original X account attribution not independently established

A Sudden Wall of Water, Mud and Rock

Preliminary satellite analysis and seismic evidence indicate the disaster began when a large mass of glacial ice and rock collapsed into a mountain river roughly 12 miles northeast of the Rasuwagadhi border crossing. The collapse generated a debris-laden surge that tore through the steep Himalayan river system.

Early reports suggested an earthquake may have triggered the disaster. The U.S. Geological Survey later said the seismic signal initially reported as an earthquake was instead generated by the collapse of glacial rock and ice and the resulting debris flow. The precise trigger for the initial collapse remains under investigation.

The flood destroyed or damaged homes, vehicles, roads, bridges and power infrastructure. Nepalese officials said dozens of bridges were destroyed and nearly 25 miles of roads were damaged, leaving some communities accessible primarily by air.

Video recorded from a roadway shows muddy floodwater and debris moving through a mountain valley as people watch from higher ground.

Source: Original X account attribution not independently established

Tourists and Pilgrims Among the Missing

The disaster struck a heavily traveled Himalayan corridor used by trekkers, workers and pilgrims. Reuters reported that 517 foreign nationals from 33 countries were among 570 tourists listed as missing in Nepal, while another 260 foreign nationals were reported missing in Tibet’s Gyirong County.

Among those reported missing in Nepal were citizens of India, the United States, Malaysia, Ukraine, Australia, Britain, Canada and numerous other countries. Nepal’s tourism authorities listed at least 65 U.S. citizens as missing. Many travelers in the region were headed toward Kailash Mansarovar, a sacred pilgrimage destination in Tibet.

Those nationality figures should be treated as preliminary. Officials have already located groups previously listed as missing, including Indian visitors and Chinese workers, and the totals may continue to change as families, tour operators, embassies and rescue teams reconcile their records.

Massive Rescue and Recovery Operation

Nepal has deployed more than 5,000 army and police personnel, along with helicopters, to search for survivors, evacuate the injured and deliver food, tents and other emergency supplies to isolated communities. Rescue teams recovered 125 people on Thursday, including 20 foreign nationals, according to Nepal’s army.

China is also conducting rescue operations in Tibet and coordinating with Nepal. International assistance and support have been pledged or provided by India, the United States, Canada and the United Nations.

Conditions remain dangerous. Chinese authorities are monitoring a dammed lake upstream in Gyirong that was already overflowing Thursday, with additional water expected as rain moves into the region. Damaged roads, deep mud, unstable slopes and high river levels continue to complicate access.

A Disaster Still Unfolding

The full scale of the loss is not yet known. Bodies have been recovered far downstream from the hardest-hit mountain communities, while relatives across multiple countries are still waiting for information about missing family members.

As search teams move into areas that were cut off by the flood, casualty and missing-person totals are likely to be revised. IRC Media will treat those figures as developing and will distinguish confirmed recoveries from preliminary reports as authorities update their counts.

IRC Media uses aggregated public data and verified sources; articles reviewed by editorial team to the best of our ability.