The death toll from a gas explosion and subsequent tunnel collapse at a hydroelectric project in India's northeastern state of Sikkim has risen to at least 20 people. Rescue operations are severely hampered by flooding and the presence of toxic gases within the collapsed tunnel, making it unlikely that any remaining trapped workers survived.

Rajiv Roka, director of the Sikkim State Disaster Management Authority, stated that out of 25 workers initially trapped, 13 bodies have been recovered. Rescuers have sighted an additional seven to eight bodies within the tunnel but have been unable to retrieve them due to the hazardous conditions. The region has also experienced heavy monsoon rains, further complicating recovery efforts.

The incident occurred at a 500-megawatt project managed by the state-owned National Hydroelectric Power Corporation (NHPC). According to the NHPC, the tunnel collapse was initiated by a sudden, explosive release of suspected methane gas trapped within the rocks, which generated dense smoke and toxic fumes.

Experts note that while accidents at large infrastructure sites are not uncommon in India, the rapid pace of development in the ecologically sensitive Himalayan region has exacerbated disaster risks. The area's seismic activity and unstable geological formations present inherent challenges for tunnelling projects.

The NHPC has pledged to conduct a thorough investigation into the cause of the explosion and collapse. The challenging conditions, including waterlogging and methane leakage, were cited by Roka as significant obstacles to retrieving the remaining victims, leading him to express doubts about any potential survivors.

This incident echoes other recent disasters in the region. In 2023, 41 workers were successfully rescued after being trapped for 17 days in a collapsed Himalayan road tunnel in Uttarakhand. Such events highlight the significant safety risks associated with large-scale construction in geologically fragile mountain environments.

The remote location of the Sikkim project and the ongoing monsoon season have added further layers of difficulty to the rescue and recovery efforts. Authorities are working to assess the full extent of the disaster and to prevent similar incidents in the future.

Questions remain about the specific safety protocols in place at the time of the incident and how they might be improved. The NHPC's commitment to a detailed investigation is seen as a crucial step in understanding the sequence of events and implementing corrective measures for future projects.