What caused the NHPC tunnel disaster in Sikkim’s Namchi? | Explained
An explosion caused by trapped methane gas in an under-construction tunnel in Sikkim resulted in 20 worker deaths. Authorities are investigating the incident, which highlights the inherent dangers of infrastructure projects in the Himalayan region.
Why it matters
The disaster raises concerns about safety protocols and geological risks in large-scale hydropower development projects.
The story so far: Toxic gases, generated by a sudden explosive release of suspected methane trapped or embedded in rocks on July 20, 2026, claimed the lives of 20 workers (till the time of reporting) in an under-construction Head Race Tunnel (HRT) of the NHPC’s 500 MW Teesta Stage VI Hydropower Project at Samardung in Sikkim’s Namchi district. Five others remained trapped about 1.5 km inside the tunnel, underlining the hazards of infrastructure development across the Himalayan landscape.
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