Buried under 170m of mud for 9 days: How two workers were rescued from Nepal’s hydropower tunnel

Nepal Army personnel and other officials rescue Kabir Maharjan from a tunnel at the Trishuli 3A hydropower project 10 days after the Bhotekohi flash floods in Rasuwa district. (PTI photo)

He stayed behind to help others

Sah later told Nepali Army officials that there were normally only four to six people in the control room, but as many as 40 to 45 may have been there when the disaster struck.

He warned the workers to run after learning that the flood was coming. He never made it out. “When there was such a big accident, it was not right for me to run away,” Sah said in a video released by Nepali authorities, according to Reuters.

For nine days, he remained in darkness underground. He told rescuers that he recited mantras to keep himself going and had contact with three or four other people somewhere in the tunnel. He also said others could be trapped farther inside.

First, rescuers had to find the tunnel

The rescue had begun with a problem that sounds simple but was anything but — the tunnel entrance had disappeared. The flood had transformed the landscape around the hydropower plant, burying the entrance beneath mud, rocks and debris.

Arnold Dix, president of the International Tunnelling and Underground Space Association and an adviser to the rescue effort, told the BBC that rescuers had never faced an operation in which they first had to work out where a tunnel entrance had gone.

They turned to whatever clues survived; old topographic maps, satellite imagery taken after the disaster, helicopter video and even surface features such as power poles.

By comparing those pieces of information, the teams triangulated the likely location and began digging.

Then they had to find the survivors

Finding the entrance was only the beginning. The tunnel itself had been blocked by huge quantities of mud and rock. Some boulders were bigger than cars, Dix told the BBC.

Rescuers used excavators to clear the way. They also resorted to controlled explosions to break through particularly difficult sections — an unusually risky step because of the possibility that people could still be alive beyond the blockage.

Dix credited the Nepal Army with carefully managing the blasts so they would not destabilise the tunnel or endanger those trapped inside.

Water presented another problem. As rescuers dug deeper, they found that sections of the tunnel were still flooded. Pumps were brought in, while trenches were dug from the tunnel towards the river to drain the water.

The final breakthrough

Eventually, rescuers created what Dix described as a narrow, person-sized passage through the debris near the top of the original tunnel. Then came the sound they had been waiting for.

In the early hours of Friday, rescuers heard what appeared to be voices from deep inside. According to local reports, they called out to those trapped and received a faint response.

Soon afterwards, they reached Sah and Maharjan. Images released by the Nepal Army showed one worker being carried out on a rescuer’s back, his face covered in mud, while the other was taken out on a stretcher. Both were flown to Kathmandu for treatment. Reuters reported that their vital signs were stable, although Maharjan was unable to move his hands or legs; Sah’s injuries were not considered critical.

The rescue is far from over

The breakthrough has not ended the search. About 900 workers are reported missing from hydropower projects in the affected region, with roughly 500 believed to be trapped in tunnels, according to authorities. At Trishuli 3A alone, about 115 workers are believed to be trapped, according to the Independent Power Producers Association of Nepal.

Rescuers are also searching other hydropower sites along the Trishuli valley. At Rasuwagadhi, teams have reached about 250 metres into one tunnel before encountering a blockage. Officials believe dozens could be trapped in a chamber where they may have access to food and water.

The rescue effort is being supported by specialists from India, China and South Korea, alongside Nepali Army and police teams.

When WhatsApp became a rescue tool

(AI-generated image)

The operation has also moved into the digital world. An engineers’ WhatsApp group set up before the disaster has become a real-time technical support network. It now has more than 500 members, including engineers and people familiar with the hydropower plants and their underground layouts.

When rescuers searching the buried Chilime hydropower plant needed information, a government official asked the group for layout drawings. Minutes later, engineers supplied drawings of the powerhouse and access tunnels.

Members have also circulated the names and phone numbers of missing workers, hoping telecom data could help establish their last known locations. News agency Reuters reviewed exchanges from the group and spoke to people involved in the rescue.

As Nepal Army spokesperson Raja Ram Basnet told Reuters, this is not a normal tunnel closure: the terrain and tunnel structures themselves have been altered by mud, rocks and debris.

Hope, and families still waiting

For the rescue teams, the survival of Sah and Maharjan has provided something they badly needed — evidence that people can remain alive underground for days after such a disaster.c Dix said the teams are now working towards what he calls a “Goldilocks zone” — an upper section of the hydropower station where there may be more space and potentially better conditions for life.

But outside the tunnels, families are still waiting. Rajesh Shrestha’s 30-year-old son Rajish, an environmental engineer at Upper Trishuli 1, remains missing.

“Whenever I look outside, I imagine seeing him carrying a bag and coming home, just as he used to,” Shrestha told Reuters.

“I am surviving on the hope that he will return.”

(With inputs from BBC and agencies)