Houses swept away to the very last brick. Inmates frantically fleeing the city’s main prison as its walls got washed away by water rising from an overflowing dam. Corpses of crocodiles and snakes floating among human bodies on main streets.

As torrential rains across Central and West Africa have unleashed the most catastrophic floods in decades, residents of Maiduguri, the capital of the fragile Nigerian state of Borno—which has been at the center of an Islamic extremists’ insurgency—said they have seen it all.