Underground fires have been burning for more than a century beneath India's largest coalfield, but in recent decades open-cast mining has brought the flames to the surface with devastating consequences for the local population.As communities are destroyed and thousands suffer from toxic fumes, what lies behind this human and environmental disaster?  Filmmakers Gautam Singh and Dom Rotheroe went to find out.The devastating impact of coal mining After the US and China, India is currently the world's third-largest energy consumer; a position that is set to consolidate in coming years as economic development, urbanisation, improved electricity access, and an expanding manufacturing base all add to demand.   Right now much of those energy needs – up to two thirds of all electricity generated – are being met by domestically produced coal, of which India has abundant reserves.