Gangtok, July 22: At least 12 workers have died after a section of the under construction Head Race Tunnel (HRT) at the NHPC Teesta Stage-VI Hydroelectric Project collapsed in Sikkim’s Namchi district, while rescue operations continue at the site.
According to the National Hydroelectric Power Corporation (NHPC), the incident occurred at around 1:04 pm on July 20 at Samardung when a suspected methane gas pocket trapped inside the rock strata suddenly burst, triggering an explosion that filled the tunnel with dense fumes and toxic gases.
A total of 25 personnel were inside the tunnel at the time of the accident. Officials said 12 casualties have been confirmed so far, while efforts are underway to evacuate and rescue the remaining trapped workers.
NHPC said it has launched emergency response protocols and is working closely with the district administration, the National Disaster Response Force (NDRF) State Disaster Response Force (SDRF) local authorities and other emergency agencies. A specialised rescue team from the Directorate General of Mines Safety (DGMS) has also joined the operation.
The corporation said its senior management has reached the accident site and is coordinating rescue efforts alongside engineering teams working round the clock to stabilise the tunnel environment and facilitate safe evacuation.
NHPC has announced that a detailed investigation will be conducted to determine the exact cause of the tunnel collapse and the suspected methane gas explosion.
Authorities said all possible efforts are being made to rescue the remaining trapped workers as operations continue.