Glacier collapse triggers deadly Nepal floods, hundreds missing

A catastrophic flash flood tore through the Nepal-Tibet border region Wednesday morning, killing at least 160 people and leaving more than 400 missing — including hundreds of foreign tourists — after a glacier collapse sent a massive wall of water, mud, and debris surging down Himalayan river valleys.

The disaster struck around 8:37 a.m. local time when an ice-rock avalanche from a glacier on the Nepal side blocked the Lhende Khola River and released a sudden surge downstream into the Bhote Koshi and Trishuli river valleys. The event was so powerful it registered as a magnitude 5.2 seismic signal on seismographs worldwide, initially misidentified as an earthquake.abcnews+3

Scale of Destruction

Nepal's prime minister's office confirmed at least 157 deaths by Wednesday evening, with 75 others wounded. On the Chinese side, state broadcaster CCTV reported at least three dead and 265 missing in Tibet's Gyirong County. Nepal's Prime Minister Balendra Shah said at least 19 bridges and 40 kilometers of roadways were destroyed.npr+3

Officials in Nepal reported 403 people missing, including 341 foreign nationals. Among those unaccounted for were 47 Americans, 133 Indians — many on pilgrimage to Mount Kailash — 34 Australians, 33 Britons, and 24 Canadians, according to Nepal Tourism Board spokesperson Sunil Sharma. Twenty-eight police personnel were also missing.aljazeera+2

"There is devastation everywhere we look," Tula Bahadur BK, a health worker in Rasuwa district, told Reuters. "The settlements next to the river have been completely swept away. Five of my own relatives are missing."reuters+1

What Caused the Flood

Göran Ekström, a geophysicist at Columbia University's Lamont-Doherty Earth Observatory, told ABC News that a landslide carried away part of a glacier, generating enormous energy that melted ice and sent floodwaters possibly 130 to 160 feet high moving at speeds up to 44 miles per hour. Dave Petley, a landslide expert writing for EOS, confirmed the seismic signal came from the collapse itself rather than a tectonic earthquake.earthsky+1

The International Centre for Integrated Mountain Development noted that the Lhende Khola had flooded twice in 14 months, with last year's event killing nine people after a glacial lake in Tibet overflowed.nbcnews+1

Rescue Efforts and Ongoing Danger

Rescue helicopters were unable to land in the hardest-hit areas of Syapru Besi and Timure in Rasuwa district due to high floodwaters. China deployed at least 574 rescuers to its side of the border, and Chinese President Xi Jinping ordered "all-out" efforts to find the missing.cbsnews+3

Authorities warned the danger had not passed. "With a blockage still lodged upstream on the Nepal-China border river, authorities warn a second flood may occur," said Qianggong Zhang, head of climate and environmental risks at the International Centre for Integrated Mountain Development. Flood alerts were issued in India's Bihar and Uttar Pradesh states.dw+1

Indian Prime Minister Narendra Modi spoke with Nepal's Prime Minister Shah and offered assistance. "India is prepared to provide Nepal with all possible types of humanitarian assistance," Modi said on social media. South Korea announced plans to send a rapid-response team after nine of its citizens working on a hydropower plant were reported missing.reuters+1