Feni, July 10 -- lying Fulgazi upazila, relentless floodwaters have submerged all 85 villages, turning the entire area into a vast expanse of water.

The swollen Muhuri, Silonia and Kahua rivers have breached eight embankments at locations such as Derpara, Uttar Sripur and Daulatpur, unleashing fierce currents that swept away roofs, fences and lives.

Among the ruins, some of the poorest villagers have fled with their cattle, poultry and children to shelter in whatever high places they could find. Families cram together in tiny rooms on the upper floors of school buildings and marketplaces -- survivors of a disaster they never caused.

In a poignant reflection of the unfolding crisis, 75-year-old Abul Kashem from Uttar Sripur, middle-aged...