INDIA – Explosion at Sikkim Hydropower Tunnel Leaves 12 Dead, 13 Still Missing

July 23, 2026

At least 12 workers have died and 13 others remain missing after a methane gas explosion caused a tunnel collapse at the Teesta Hydroelectric Project in India’s northeastern state of Sikkim. The incident occurred on Monday at the 500-megawatt hydropower project in Samardung village, near the Chinese border.

Rescue operations continued into Tuesday as teams from the National Disaster Response Force (NDRF) worked to locate those still trapped. Their efforts were hampered by dangerous levels of methane, carbon monoxide and hydrogen sulfide inside the tunnel, along with rising water. Rescue personnel entered the site using specialized breathing equipment and night-vision gear to safely navigate the hazardous conditions.

Officials said 21 laborers were working inside the tunnel when the explosion occurred. Two workers escaped shortly after the blast, while six power utility officials who later entered to assist with rescue efforts also became trapped.

Authorities believe the explosion was caused by a buildup of methane gas. Sikkim Chief Minister Prem Singh Tamang, who visited the disaster site, said early findings support this theory. Survivors described hearing a loud explosion before the tunnel partially collapsed, sending debris crashing down.

One of the survivors, 38-year-old Gandura Oraon, said he and several coworkers were eating lunch when the blast occurred. They escaped by driving out of the tunnel in the vehicle that had delivered their meal. Oraon said they urged their supervisor to leave with them, but he instead went toward the explosion to assess the situation and was later found dead.

The Teesta Hydroelectric Project is being built in the Teesta River basin, a geologically unstable area of the Himalayas. The region is prone to earthquakes and is characterized by fractured rock formations and underground gas pockets. According to experts, these conditions make tunneling projects particularly dangerous, increasing the risks associated with large-scale infrastructure development.

India