Sikkim has been devastated by a flash flood in the Teesta river that has ravaged towns like Chungthang, Dikchu, Singtam and Rangpo. There has been destruction further downstream in West Bengal as well. In this special report, we follow the trail of devastation from the upper reaches of the river all the way upto Teesta Bazaar in West Bengal and also cover the damage to the crucial National Highway 10 that connects Sikkim to the rest of the country.