Dhaka, Nov. 29 -- "They burned our homes. Why don't you write about that? Just check Facebook."

Standing amid the charred ruins of Dhaka's Korail slum, a young man identifying himself only as Ashraf hurled the familiar accusation: his voice edged with anger, his eyes full of distrust.

Every time a fire rips through a slum in Dhaka, similar questions echo through the smoke. Newspapers cite the refrain: "Accident or arson?" The pattern is by now routine.

In old Dhakai films, villains were often shown torching slums as they laughed, while the hero raced in to rescue people.

The difference is that, in real life, even after multiple investigations, the villains are never found.

For Dhaka's slum dwellers, survival means rebuilding again an...