New Delhi, Sept. 20 -- Nepali Khuti and Bonqual Balichapori: By 12pm, the water was already at their necks. Krishna Prasad Sharma's wife and two sons had been calling for help while he delivered milk in nearby Sivasagar. None of them could swim, and the current tearing through Nepali Khuti, a dairy farming village in Assam, was strong enough by then to take whatever stood in its way. It was neighbours, a mother and her son, who came without hesitating, breaking through the ventilator of the trapped family's house with a bamboo pole and hauling all four onto the tin roof. There they sat out the rest of 19 July, watching the village disappear beneath them.

Below their rooftop perch, in a cowshed slowly filling with water, 24 Jersey cows st...