At least 10 people have died and 17 others remain missing after a suspected gas explosion triggered the collapse of a tunnel under construction at a hydropower project in India’s northeastern state of Sikkim, officials said. The India tunnel collapse struck on Monday at Samardung village, near the border with Bhutan and Tibet in the Himalayas.
What Caused the Tunnel Collapse
Multiple workers were carrying out construction on the 500-megawatt project for the state-owned National Hydroelectric Power Corporation (NHPC) on the Teesta River when the blast occurred. Survivors told authorities they heard a loud explosion before debris came crashing through the tunnel, trapping dozens inside.
NHPC said in a statement that a sudden burst of gas, suspected to be methane trapped or embedded in surrounding rocks, caused the blast. As news of the accident spread, six NHPC officials entered the tunnel to assist with rescue efforts but became trapped themselves, officials said.
Rescuers Battle Toxic Gas to Reach Trapped Workers
“We have recovered 10 bodies so far, and 17 others are feared trapped,” local police chief Sonam Dolma said.
Rescue teams, including the National Disaster Response Force (NDRF), have struggled to reach those trapped because of hazardous conditions inside the tunnel, where toxic gases have accumulated. NDRF official Nitin Kumar told reporters at the scene that rescuers found methane, carbon monoxide and hydrogen sulphide inside the tunnel. He said rescue workers were using specialised breathing equipment as they searched for survivors amid dangerous air conditions.
A Pattern of Tunnel Disasters in the Himalayas
Construction accidents are not uncommon in India, particularly in the Himalayan region, where seismic activity and unpredictable underground conditions make tunnel projects especially risky. In 2023, 41 workers were trapped for 17 days before being rescued after a section of a tunnel collapsed in the northern state of Uttarakhand.
Experts told the Associated Press that the Teesta River basin, where the Sikkim hydropower project is being built, lies in a seismically active region marked by young, fragile rock formations riddled with fractures and underground pockets that can trap and accumulate gases, creating the conditions for explosions like Monday’s.
