Rescuers battled methane, carbon monoxide, mud and darkness as the death toll in the south Sikkim tunnel explosion rose to 13, with 12 workers still missing. | India News

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

Incident occurred on Monday in Sikkim, where workers were constructing a tunnel for a state-run hydropower project; official says around 25-27 people trapped.