IN the tsunami of December 2004, people heard a strange, deep rumbling before columns of the sea came in. In 2008, the people of north Bihar had no such warning. The river was silent and swift, rising from a deceptive two feet to nearly eight feet in a matter of hours, trapping lakhs of people in remote villages in the districts of Purnea, Madhepura, Araria, Supaul, Saharsa and Kul.