Rescue workers on Tuesday began the process of inserting wide steel pipes through the rubble of the collapsed under-construction tunnel on the Chardham route to bring out the 40 labourers trapped inside for two days now, officials said.

The plan was to push through 900-mm diameter sections of mild steel pipes -- one after the other -- into the rubble using drilling equipment and create an escape passage for the workers, who officials say are safe and being provided with oxygen, water, food packets and medicines through tubes.

The son of Gabbar Singh Negi, one of the trapped labourers, was allowed to speak to his father for a few seconds on Tuesday. "He said they were safe. He asked us not to worry…," Akash Singh Negi told PTI.

A local priest was also asked to perform a puja for the early and safe evacuation of the stranded workers.

A part of the tunnel being built between Silkyara and Dandalgaon on the Brahmakhal-Yamunotri National Highway caved in on Sunday morning following a landslide. The 30-metre collapsed section is 270 metres from the mouth of the tunnel from the Silkyara side, the state emergency operation centre said in Dehradun.

Disaster Management Secretary Ranjit Kumar Sinha said the authorities have set a target of rescuing the trapped labourers by Tuesday night or Wednesday.

The officials said mild steel (MS) pipes and the auger machine arrived at the spot in the early hours of Tuesday. A platform is being prepared for the auger drilling machine, the officials said, adding that the MS pipes have a diameter of 900 mm.

An expert team of five engineers from the irrigation department is on the spot to oversee the insertion process of the MS pipes through the rubble, the state emergency operation centre said.

A team of 160 rescuers from the NDRF, SDRF, ITBP, BRO, RAF and the health department have been on the spot since Sunday, working relentlessly to reach the trapped workers.

Contact is being maintained with the trapped labourers and the assurance that a huge rescue operation is being carried out by various agencies to evacuate them has also boosted their morale, NHIDCL Executive Director Col (retd.) Sandip Sudehra said.

The National Highways & Infrastructure Development Corporation Limited (NHIDCL) is the agency engaged in building the tunnel.

Uttarkashi's Chief Medical Officer RCS Panwar said a six-bed temporary hospital has been set up near the tunnel and 10 ambulances with medical teams stationed to provide immediate medical care to the trapped workers after their evacuation.

According to a list of the trapped workers issued by the District Emergency Operation Centre, 15 are from Jharkhand, eight from Uttar Pradesh, five from Orissa, four from Bihar, three from West Bengal, two each from Uttarakhand and Assam, and one from Himachal Pradesh.

A team of experts headed by the Uttarakhand Landslide Minimisation and Management Centre director are examining the affected part of the tunnel and the hill above to ascertain the reasons behind the cave-in, an official statement said.

The team also includes scientists and officials from the Uttarakhand State Disaster Management Authority, the Geological Survey of India, the Central Building Research Institute, IIT-Roorkee and the Wadia Institute of Himalayan Geology.

Chief Minister Pushkar Singh Dhami is constantly taking updates on the progress of rescue operations, the statement said.

He held a meeting with senior officers at his residence and asked them to coordinate with officials present at the spot and provide them with relief materials at the earliest.

Meanwhile, environmental experts have warned that horrific incidents like this would continue to happen if ecological concerns were not addressed.

Ravi Chopra, who resigned last year as the chairman of a Supreme Court-appointed high-powered committee on the Char Dham all-weather road project, said it was necessary to first address ecological concerns for development in the Himalayas.

"Sustainable development demands approaches that are both geologically and ecologically sound. Unless this balance is achieved, such horrific incidents will continue to happen," Chopra told PTI.

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