India tunnel collapse at a hydropower project kills 10 as 17 remain missing
A suspected methane explosion has caused a tunnel collapse at a hydropower project in India's Sikkim state, killing at least 10 workers and leaving 17 missing. The incident occurred at a 500-megawatt facility operated by the state-owned National Hydroelectric Power Corporation on the Teesta River.
A catastrophic tunnel collapse at a hydropower construction site in India's northeastern Sikkim state has resulted in significant casualties and an ongoing rescue operation hampered by hazardous underground conditions. The incident occurred on Monday at Samardung village near the borders with Bhutan and Tibet, when a suspected gas explosion triggered the structural failure of a tunnel under construction at a 500-megawatt facility operated by the National Hydroelectric Power Corporation (NHPC) on the Teesta River.
According to NHPC officials, the blast was caused by a sudden burst of methane gas that had accumulated within rock formations inside the tunnel. Multiple construction workers were engaged in various phases of the project when the explosion occurred, with survivors reporting hearing a loud blast before debris collapsed through the tunnel, trapping numerous individuals. The initial rescue response was complicated when six NHPC officials who entered the tunnel to assist became trapped themselves.
Rescue operations have been severely constrained by dangerous atmospheric conditions within the tunnel, where toxic gases including methane, carbon monoxide, and hydrogen sulphide have accumulated. Local police chief Sonam Dolma confirmed that 10 bodies have been recovered thus far, with 17 individuals feared to remain trapped. The National Disaster Response Force (NDRF) has deployed specialized breathing equipment as rescue teams attempt to navigate the hazardous environment and locate survivors.
Construction accidents remain relatively frequent in India, particularly in the Himalayan region, where seismic activity and unpredictable subsurface conditions create elevated risks for tunnel projects. The Teesta River basin, where this hydropower facility is being constructed, is situated in a seismically active zone characterized by young, fragile rock formations containing numerous fractures and underground cavities capable of trapping and accumulating gases. A precedent for extended entrapment occurred in 2023 when 41 workers were rescued after 17 days following a tunnel collapse in Uttarakhand state.
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