Rescue teams in Nepal are in a desperate race against time to reach hundreds of workers believed to be trapped inside mud-filled tunnels at a series of hydropower plants, nearly a week after catastrophic floods swept through the Nepal-Tibet border region. The death toll has risen to 939 on the Nepali side, with a further 16 confirmed dead in Tibet. More than 4,400 people remain listed as missing across both sides of the border — including over 592 foreign nationals and more than 30 British citizens.

The disaster was triggered on August 26 when a glacier collapse sent a torrent of ice, rock and mud surging down the Trishuli River valley, striking the mountainous districts of Rasuwa and Nuwakot in northern Nepal. Authorities estimate that around 600 workers remain trapped in tunnels at 12 hydropower projects damaged by the floods, with oxygen levels inside an urgent concern. Some workers were able to call for help when the flooding began, and those who escaped reported colleagues still stranded underground. Rescuers, including Nepali and Chinese military personnel alongside experts from India, South Korea and Australia, have been using explosives to blast into hillsides, pumping air into tunnels and deploying earth-moving equipment to dig through deep deposits of mud and debris. Around 250 people were pulled to safety from the Upper Trishuli hydroelectric project over the weekend, and more than 279 workers have been rescued from hydropower sites in total. With over 40 bridges destroyed, helicopters have been essential for evacuations, while India and China are supplying prefabricated truss bridges to restore ground access.

Experts warn that the survival window is narrowing sharply. The first 72 hours are considered critical, and six days on, the lack of clean water poses the most immediate threat.