"Layer upon layer of miracles" to find tunnel survivors, Nepal rescue adviser tells BBC

A tunnelling expert involved in the rescue operation at a blocked hydropower tunnel in Nepal has described the challenges that led to the discovery of two survivors. Arnold Dix, president of the International Tunnelling and Underground Space Association, has advised local authorities on how to dismantle the rubble that had swallowed the tunnel.

Finding the entrance

The flood buried the original hillside entrance deep underground, turning the landscape into an unrecognisable jumble of mud and rock. The rescue team used satellite images, old topographic maps, helicopter footage and visible on‑ground features such as power poles to triangulate its position before starting excavation.

Clearing the debris

The tunnel had been filled with mud, rocks, and water, with some debris larger than cars. Explosives were carefully detonated – a move rarely used because it risks destabilising the tunnel. The Nepalese army managed the blasts with precision, while machinery backed by pumps removed flooding water.

Sentences of hope

During the early hours of Friday, rescuers heard faint voices. Calls for reassurance were replied to with a quiet “okay”. This exchange confirmed the presence of survivors: Sanjaya Shah and Kabir Maharjan were subsequently pulled out of a narrow passage created at the rubble’s top.

Prospects for the remaining trapped

Rescuers estimate a further 150 m of tunnel to be dug before the hydropower station deep within the mountain. The flood’s debris, water intrusion, and the possibility of a secondary flood outside create continual risks. Nevertheless, the successful rescue has energized the team to continue with a ‘Goldilocks zone’ strategy – a corridor less risky for life.

The operation, measured by different lenses, illustrates a fusion of local determination, international engineering expertise, and the global humanitarian commitment to saving lives in extreme circumstances.