Three more bodies were recovered from the under-construction tunnel for the Teesta Stage-VI Hydel Project in Samardong in South Sikkim on Wednesday, where a methane explosion occurred earlier this week, raising the death toll to 15, even as 10 people remain missing, officials said.
Rescuers, who entered the tunnel with breathing apparatus in search of trapped survivors, described the tunnel as extremely dark, hot, full of toxic gases and muddy.
“The conditions are very bad inside. It is very dark and hot inside. The tunnel is full of toxic gases like methane and carbon monoxide. The floor of the tunnel is full of mud and our legs often got stuck,” said a member of the rescue team of Coal India Ltd.
At least 25 workers were working inside the Adit-3 of the 15-kilometre-long tunnel, connecting the barrage at Siwarni to the power plant at Tarkhola in south Sikkim, when the methane explosion occurred around Monday afternoon.
“We recovered three bodies on Wednesday. The death toll is 15. At least 10 people are still missing. Rescue teams from NDRF and Coal India Limited are still working at the site,” Namchi District Superintendent of Police Sonam D Bhutia said.
The dead were migrant workers from West Bengal, Jharkhand, Punjab, Assam and Uttarakhand. One worker from Sikkim also died.
Members of the CIL rescue team claimed to have spotted at least eight more bodies inside the tunnel on Tuesday.
“Our gas detectors are equipped to detect and measure the levels of four gases – hydrogen sulphide, oxygen, methane and carbon monoxide. During rescue operations, we detected high doses of methane and carbon monoxide. Normally, the site is evacuated if the lower explosive limit (LEL) of these gases reaches 20%. But the doses of carbon monoxide and methane are much higher in the tunnel, making work difficult,” said an official working in the tunnel. location.
Rescuers must enter the tunnel wearing self-contained breathing apparatus that help maintain a constant supply of oxygen during long-range rescue operations. Each device weighs approximately 15 kg.
People familiar with developments at the accident site said that search and rescue operations were halted for several hours due to the accumulation of water and mud at the site.
Another official said: “While digging tunnels, a lot of mud, silt and water come out. They are pumped out. But since the explosion damaged equipment and pipelines, it was not possible to pump out the mud and water, so the ground became muddy and water accumulated in pockets, hampering rescue operations.”
The rescuers who entered the scene said that it was very difficult to walk because their legs remained stuck in the mud, and every time they had to use something to pull their legs out, making the rescue operations more difficult and difficult.
“We have deployed earth bulldozers,” an official said. “Our engineers are repairing damaged pipes so that water and mud can be pumped out and rescuers can enter. Rescuers wear 15-kg masks and respirators equipped with oxygen cylinders to go inside the dark tunnel and search for survivors and bodies.”
