Sikkim tunnel tragedy: Death toll rises to 11, eight more bodies located at NHPC Teesta Stage-VI project

The death toll in the tunnel disaster at NHPC's under-construction Teesta Stage-VI Hydroelectric Project in Sikkim's Namchi district rose to 11 on Tuesday evening after rescue teams recovered another body from inside the collapsed tunnel.

Officials said eight more bodies have been located within the tunnel, with recovery operations underway amid hazardous conditions.

The tragedy unfolded around midday on Monday at the project site in Samardung, Jholungay, when a reported methane gas explosion occurred during excavation work, trapping several workers deep inside the under-construction tunnel. Rescue efforts have since been hampered by low oxygen levels, unstable ground and poor air quality.

Chief Minister Prem Singh Tamang announced that the state government has constituted a Special Investigation Team (SIT) to probe the cause of the disaster. He also announced an ex gratia of ₹4 lakh for the families of each deceased worker and ₹50,000 for those injured.

Rescue and recovery operations are being jointly carried out by the National Disaster Response Force (NDRF), State Disaster Response Force (SDRF), Sikkim Police, Fire and Emergency Services, the district administration and NHPC.

Rangpo Fire Services, which first entered the tunnel, had to withdraw after oxygen levels dropped dangerously low, with some rescue personnel reportedly falling ill due to exposure. Subsequent attempts by NDRF teams were also slowed by toxic air, debris and unstable tunnel conditions.

A specialised chemical analysis team has reached the site to investigate the reported methane gas explosion. Its findings will assist the SIT in determining the sequence of events and the cause of the accident.

Senior officials, including the District Collector, continue to supervise the operation from the site. Heavy machinery and specialised rescue equipment have been deployed as teams carefully work to recover the remaining bodies while ensuring the safety of rescue personnel.

Authorities said the operation remains challenging, but efforts are continuing round the clock to retrieve all those trapped and complete the investigation into one of Sikkim's worst industrial disasters in recent years.