Nature: In the wake of Cyclone Aila in 2009, swollen seas washed over the delta of the Ganges and Brahmaputra rivers. The storm surge breached the embankments surrounding a small island that was home to 10,000 families, turning the land into a muddy hell. The deluge of salty water washed out fields, homes, roads and markets just as people had begun to recover from the damage caused 18 months before by Cyclone Sidr. Many migrated to nearby cities. And thousands more took shelter on what remained of the embankments,...