New Delhi: At least 10 workers have been killed and 15 others remain trapped after a tunnel collapse triggered by a suspected methane gas explosion at an under-construction hydroelectric project in India’s northeastern state of Sikkim, as rescue teams race against time amid hazardous conditions.
The accident occurred on Monday inside a tunnel being built for the state-run National Hydroelectric Power Corporation (NHPC) project on the Teesta River in Samardung village.
According to NHPC, a sudden release of methane gas trapped within underground rock formations is believed to have triggered an explosion deep inside the tunnel, causing a collapse that filled the passage with dense fumes and toxic gases.
Authorities estimate that between 25 and 27 workers and project officials were inside the tunnel when the incident occurred. By Tuesday, rescue teams had recovered 10 bodies, while 15 workers remained unaccounted for.
Sikkim State Disaster Management Authority Director Rajiv Roka said the rescue operation was being severely hampered by high concentrations of toxic methane gas, forcing only specially equipped teams carrying oxygen supplies to enter the tunnel.
“Aggressive rescue operations are under way, but the problem is there’s a lot of gas present there,” Roka said, adding that the chances of finding survivors were becoming increasingly slim as rescuers battled dangerous conditions underground.
Photographs released by the Sikkim government showed emergency personnel wearing protective suits unloading oxygen cylinders, ropes and specialised rescue equipment at the disaster site.
The state government said multiple agencies were carrying out rescue operations on a war footing, while a specialised team trained in mining and tunnel accidents was flown in to assist local responders.
The exact cause of the explosion remains under investigation. Officials said it most likely resulted from a natural release of methane gas trapped within underground rock formations, although recent heavy monsoon rains in the Himalayan region may also form part of the investigation.
Prime Minister Narendra Modi expressed condolences over the tragedy and assured the Sikkim government of “every possible assistance” from the central government to support rescue efforts and provide relief to those affected.
Tunnel and infrastructure accidents remain a recurring concern in India, particularly in the ecologically fragile Himalayan region, where experts have warned that rapid infrastructure development alongside challenging geological conditions has increased the risk of disasters.
The latest tragedy comes less than three years after a high-profile rescue operation in Uttarakhand, where 41 workers were successfully rescued after spending 17 days trapped inside a collapsed road tunnel.
