Residents of Borapahari village burn raw coal to process it into charcoal . Coal fires rage just below the surface of the ground, making it too hot to walk with naked feet. Noxious gases spew up from fissures, rendering the environment toxic. Residents who live above the furnace make $2 a day collecting small chunks of coal that they sell to illegal middlemen. One or two houses collapse annually into vast underground caverns left unfilled by abandoned mining operations.