At least 20 workers have died in a tunnel collapse at an under-construction hydroelectric project in Sikkim's Namchi district, as rescue teams battle toxic gas to locate survivors.

The tunnel is a part of the National Hydroelectric Power Corporation’s (NHPC) Teesta Stage VI hydroelectric power project | India News

Seven workers died after a landslide blocked the entrance of Sikkim's Samardung tunnel, causing a gas leak that hampered rescue efforts for trapped individuals.

Ten people died and twenty-five personnel were trapped after a methane gas burst. The explosion occurred inside an under-construction tunnel at the Teesta Stage VI Hydroelectric…