Sikkim Tunnel Disaster: 10 Dead, 25 Trapped After Landslide Triggers Collapse in Namchi

NAMCHI, SIKKIM — A massive rescue operation is underway in the Samardung area of Jholungey after a violent landslide triggered a structural collapse inside an under-construction hydroelectric project tunnel, leaving at least 10 workers dead and dozens more trapped deep underground.

The incident occurred at the ADIT-3 tunnel, a critical segment of the National Hydroelectric Power Corporation’s (NHPC) Teesta Stage-VI Hydroelectric Project.

The disaster unfolded on Monday afternoon, July 20, 2026 following an accumulation of hazardous methane gas inside the subterranean passage. Officials report that the gas naturally emanated from underground rock strata about 1.5 kilometers into the shaft.

An attempt to vent and release the trapped gas reportedly sparked a powerful explosion, which destabilized the surrounding terrain and unleashed a massive landslide that blocked the tunnel's entrance, effectively cutting off the escape route for those inside.

While some workers managed to escape immediately following the initial blast, approximately 25 individuals—including NHPC personnel and contractors from Patel Engineering Ltd.—became stranded deep within the mountain.

Emergency responder teams from the National Disaster Response Force (NDRF), State Disaster Response Force (SDRF), Sikkim Police, and local Fire Services rushed to the scene, but the rescue operation has faced severe setbacks. Initial rescue attempts by first responders had to be abandoned when several personnel experienced extreme dizziness and breathing difficulties due to low oxygen levels and lingering toxic methane.

Furthermore, heavy, continuous rainfall across the Namchi district has triggered additional terrain instability, continuously threatening the safety of the active rescue lanes. To break the deadlock, specialized teams equipped with advanced gas-protective gear have been deployed from neighboring West Bengal to help navigate the narrow, toxic passageways.

By Tuesday morning, authorities confirmed that 10 bodies had been successfully recovered from the wreckage. Seven of the victims have been identified as laborers originating from various regions, including West Bengal, Uttarakhand, Punjab, Assam, and local areas of Namchi.

Sikkim Chief Minister Prem Singh Tamang-Golay is closely monitoring the development and confirmed that all available state resources are being directed toward the site.

"I am deeply saddened by the tragic incident at the under-construction tunnel... My heartfelt condolences go to the families of the workers who have lost their lives," the Chief Minister shared, adding that specialized agencies are working tirelessly to reach the remaining trapped personnel.

Prime Minister Narendra Modi also spoke with Chief Minister Tamang on Tuesday morning, expressing deep concern for the trapped victims and assuring full assistance and solidarity from the Central Government as rescue operations enter a critical phase.