Rescuers in India are trying to reach five workers still trapped after a blast at an under-construction hydropower tunnel, as the death toll rises to 20. Multiple reports describe the incident occurring following a suspected methane explosion inside the tunnel’s rock strata. The blast collapses part of the tunnel and triggers additional hazards that complicate rescue efforts. Rescuers face flooding and the presence of toxic gas in the collapsed passage, according to accounts cited by international media, which reduce the likelihood of survival for any remaining trapped workers. Emergency teams continue search and rescue operations within the damaged tunnel while assessing the conditions underground. Authorities and responders treat the explosion as linked to methane trapped in the geology of the tunnel, but the exact cause and circumstances are still being investigated as part of ongoing response and recovery work. The incident highlights the risks involved in tunnel construction and underground energy projects, particularly where ventilation and gas monitoring are critical.