Australian geologist and international rescue expert Arnold Dix says the breakthrough in Nepal’s underground flood disaster was “a fantastic day”, praising soldiers who blasted through boulders the size of cars to reach men trapped in total darkness for more than a week.

“What a fantastic day yesterday was,” Dix said.

“A week and a half of planning, so much work — and we got it right.”

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Nepal’s deadly flood was triggered when a glacial lake burst high in the Himalayas, sending a violent surge of water, ice and debris down the valley.

The collapse unleashed a fast‑moving torrent that tore through villages, hydropower sites and road networks, wiping out entire sections of infrastructure in minutes.

Dix said he had been sitting in his office a week and a half earlier “trying to work out where to dig a hole” before arriving in Kathmandu.

“We managed to actually identify where to dig to get down through the boulders — they’re bigger than a car. We managed to blow up the top of the hole. When I say ‘we’, I didn’t do it. I’m just helping on the team. But those army guys who are there — oh my God, what they have done is just amazing,” he said.

The Nepali army rescued two workers trapped for nine days inside a tunnel at a hydropower project. Credit: AAP

Authorities estimate more than 1000 people remain missing, with the true toll still unclear as crews struggle to reach remote communities cut off by landslides and destroyed bridges.

The force of the outburst flood pushed debris deep into tunnel systems and underground worksites, trapping workers and villagers who had sought shelter as the water hit

Dix said the men rescued had been trapped underground “in total darkness” since before he first spoke publicly about the operation.

“I didn’t come here for holiday, so obviously I think we can do it,” he said.

“And I was saying during the week when everyone was calling it a recovery and not a rescue — no, no, this is a rescue.”

Two workers trapped inside a tunnel at a hydropower project have been rescued alive in Nepal. Credit: AAP

Rescue teams have been working in dangerous conditions, battling unstable ground, repeated rain bands and rising river levels that continue to threaten access points.

Hydropower facilities, roads and communication lines have been heavily damaged, slowing the search effort and complicating attempts to confirm how many people were inside the affected zones when the glacier failed.

Dix described the tunnel where survivors were found as once being halfway up a hill.

“That little arch — before the avalanche, before anything happened — that was halfway up a hill. That was where you used to drive up. I’ve got video footage as that wall of water was coming, with people running up a hill to get into that, which is now under the level of the river.”

He said the rescued men needed careful treatment.

“They haven’t seen night or day. They haven’t had any food. All they’ve had is a will to live. And you see how happy everybody is there? That’s having a good day. That is a really good day.”

Dix said the Nepalese soldiers on the ground were relentless.

“These are incredibly strong‑willed people with an incredible will to live. Those soldiers you see there — they will do anything to rescue their people. The team I’m working with are just fantastic. The fact that they’ve been able to do this is just amazing.”

He warned the operation remained dangerous.

“We’ve got rain falling at the moment. The river is now higher — it used to be lower — now it’s higher than that hole you see in the ground,” Dix said.

“There’s a possibility that if we get another flash of water come up the river, it will go in there. That means the rescuers who are in there will have water come in behind them.”

Dix warned that the rescuers may have water coming in behind them due to heavy rain Credit: Sunrise

Dix said crews were digging towards their next mission.

“We’re heading for a power station at the moment. We haven’t got to the power station yet. We’d identified in the power station — sort of up at the top — what I’m calling the Goldilocks Zone. We’ve got about another 150 metres to go to do that,” he said.

“And while we’ve got hope — and we do — then that’s why I’m here. Despite the attractions of Monbulk (where Dix is from), and even though this isn’t a holiday, I’ve come because there is still a very real possibility that we’re gonna find more people.”