The devastating flash flood that struck Nepal on Wednesday morning was not caused by an earthquake, but rather by a glacial collapse and debris flow triggered by a landslide, according to the United States Geological Survey (USGS).

On Wednesday evening, the agency stated that the seismic tremor initially identified as an earthquake was actually a "glacial collapse and debris flow," which subsequently wreaked havoc downstream, as reported by NDTV.

According to USGS calculations, the event was initially detected as a 4.4 magnitude earthquake near the Nepal-China border north of Kathmandu at 8:37 AM Nepal time.

The agency later clarified that no earthquake occurred; rather, the event was a glacier collapse and debris flow.

Preliminary analysis of satellite imagery from Planet Labs also revealed that a landslide of ice and rocks in the Lende River—approximately 20 kilometers northeast of the Nepal-China Rasuwagadhi border crossing—generated a debris-laden flood.

The Lende is a tributary of the Bhote Koshi River, which flows from China into Nepal. The resulting flash flood has left over 157 people dead. The USGS later recorded the energy of this landslide as equivalent to a 5.2 magnitude earthquake.

Rescue and Relief Operations in Nepal

Relief and rescue operations are ongoing in Rasuwa and other affected areas following the flood. The Nepal Police have recovered 157 bodies, and efforts are underway to evacuate families from high-risk flood zones.

According to the Ministry of Tourism, at least 403 tourists were unaccounted for hours after the disaster, 341 of whom are foreign nationals.

The Tourism Board reported that among the missing foreigners are 142 Indian citizens, along with nationals from Australia, Britain, Malaysia, the Netherlands, Portugal, South Africa, South Korea, and the US.

Rescuers are working rapidly to locate survivors and bodies buried under the mud. Prime Minister Balendra Shah has promised to deploy all government resources for relief and rescue operations.

Casualties in Tibet

China’s state broadcaster reported that three people were killed and 265 are missing in the Gyirong area on the Tibetan side.

Security camera footage captured on the Tibetan side of the Nepal-Tibet border shows people frantically running for safety moments before buildings and vehicles were destroyed by a torrent of rocks, mud, and water.

Local residents from affected areas in Nuwakot and Dhading have gathered outside a Nepal Army training center to seek information about their missing relatives. Helicopter rescue operations are being conducted from this very center.

Due to a power outage caused by damaged electrical infrastructure, police outside the barracks gates are using mobile phone flashlights to record the names of missing persons.

Houses, trees, and vehicles in the disaster-stricken areas have been submerged or crushed under mud and landslides. Helicopters were seen flying over the area throughout the day, working to evacuate survivors to safety.