Full Breakdown
Tunnel Collapse at the Teesta Hydropower Project in Sikkim
7/22/2026, 12:37:26 AM
Core Event
On Monday, a suspected gas explosion ripped through a tunnel under construction for the 500-megawatt Teesta hydroelectric project in Samardung village, a remote area of Sikkim near the Chinese border. The blast caused a partial collapse, trapping workers inside and prompting an emergency response from the National Disaster Response Force (NDRF).
Background & Context
Construction accidents are frequent in India’s rapidly expanding infrastructure sector, especially in the Himalayas where young, fractured rock formations and seismic activity create hazardous underground conditions. The Teesta River basin, the site of the project, lies in a region known for pockets of ancient gases. Similar incidents have occurred nearby, including a coal-mine explosion in Meghalaya that killed at least 18 workers in February and a 2023 tunnel collapse in Uttarakhand that held 41 workers for 17 days.
Data & Statistics
- Project capacity: 500 MW.
- Workers inside the tunnel at the time of the blast: 21.
- Six National Hydroelectric Power Corporation (NHPC) officials entered the tunnel to assist rescue efforts, bringing the total number of people trapped to 27.
- Toxic gases detected: methane, carbon monoxide, and hydrogen sulfide.
- Rescue teams could operate inside the tunnel for only about 15 minutes per shift due to hazardous air quality.
Official Statements & Responses
State Chief Minister Prem Singh Tamang visited the site and said the explosion was likely caused by a buildup of methane gas. NDRF official Nitin Kumar reported the presence of methane, carbon monoxide and hydrogen sulfide, noting that rescuers required oxygen gear and could remain inside for short intervals. Civil official Anupama Tamling relayed that survivors heard a loud explosion before debris fell, and that two workers managed to escape the initial collapse.
Conflicting Reports & Gaps
Two outlets provided differing casualty figures. One source reported at least 12 deaths with 13 people missing, while another cited at least 11 deaths and 14 missing. Both agree that rescue teams continue to search for survivors among the remaining trapped individuals, but the exact toll remains unsettled. No further official update on the missing count has been released.
