A suspected gas explosion ripped through a tunnel under construction at a hydropower project in India's northeastern Himalayan state of Sikkim on Monday, killing at least 10 people and leaving 17 missing.
The blast struck the village of Samardung on the Teesta River, roughly 40 kilometres from the state capital Gangtok, collapsing the worksite of state-owned National Hydroelectric Power Corporation. Rescue operations were immediately hampered by a toxic build-up of gases — officials from the National Disaster Response Force said methane, carbon monoxide and hydrogen sulphide were detected inside the tunnel, and several rescuers have lost consciousness while attempting entry.
Six senior NHPC personnel who entered the tunnel to assist rescue efforts also became trapped. Crews continue to search for the missing workers and staff believed buried in the rubble.