1. Destruction on land - Lava, Lava rocks flying
2. Pollution - The smoke in the air
3. The environment surrounding the volcano
Because of Dhaka's position below sea level the city experiences yearly flooding, particularly around the monsoon seasons and has the constant threat of rising sea levels, which would of course cause more flooding.
Their progress and wealth is highly dependent on the harvests, and the price of grain. They probably have to import some industrial products and if they had a bad year (weather, other catastrophies, poor technology) they can't get the necessary amount of industrial products in exchange for their surplus e. g. in grain. There are so many standards and requirements about the quality of food production that no country can survive solely on agriculture without high quality technology (machines, unharmful fertilizers, research-based breeding, etc.).
Big Bang Theory, creation by deities (God, Buddha, etc) and Darwinism I would think.