At least ten workers have been killed and several others remain trapped after a methane gas explosion triggered a tunnel collapse at an under-construction hydroelectric project in Namchi district, Sikkim (a small Himalayan state in northeastern India), on Monday. The blast occurred inside the ADIT-3 tunnel of the NHPC Teesta Stage VI project while workers were attempting to release accumulated methane gas roughly 1.5 kilometres from the tunnel entrance; the resulting landslide blocked the exit, trapping an estimated 25 workers. Multi-agency rescue teams including the National Disaster Response Force, state disaster units, and specialist teams from neighbouring West Bengal are working to recover victims and reach survivors, with Prime Minister Narendra Modi personally calling the state's chief minister to pledge federal assistance.