Excavators began drilling with heavy machinery on Tuesday to fix a wide steel pipe that will help pull out almost 40 Indian workers trapped inside a collapsed Himalayan highway tunnel that caved in two days ago in the north Indian state of Uttarakhand.
The 4.5-km tunnel, which was being built on a national highway that is part of a popular Hindu pilgrimage route, caved in around 5:30 am on Sunday (2400 GMT on Saturday).
"We have been supplying food, water and oxygen to the trapped workers and the officials are in continuous touch with all of them," Devendra Singh Patwal, a disaster management official said.
Excavators have been removing debris for two days to carve out a path to reach the workers and had been awaiting delivery of a wide steel pipe, which will be pushed into an opening of excavated debris to safely pull out the workers.
Patwal said it was not easy to ascertain the time required to pull out the workers.
A team of geologists from the state government and educational institutions had arrived to determine the cause of accident, he added.
There were around 50 or 60 workers inside the tunnel and around 10 or 20 of them got out after their shift ended as they were closer to the exit and the rest were trapped after the collapse, the Indian Express newspaper reported, quoting one construction worker who made it out safely.
"Initially, we thought it might be a minor collapse and began removing the debris however we could," Rajeev Das, the worker, told the newspaper. "But soon, we realised it was a challenging search and rescue (mission)."
The region is prone to landslides, earthquakes and floods and the incident follows events of land subsidence in the state that geologists, residents and officials have blamed on rapid construction in the mountains.
The work on the tunnel stretch commenced in 2018 and was initially intended to be completed by July 2022, which has now been delayed to May 2024, an Indian government statement said.