Cyclones striking Bangladesh tend to cause immense devastation because the country's topography conspires to amplify their impact. Thus, the 1970 storm, nicknamed the Bhola Cyclone, proved to be one of the worst natural disasters in recorded history, even though it made landfall as only a Category 3 storm. Fatality estimates range from 300,000 to 1 million people, although most put the tally at closer to 500,000.
Bangladesh's delta is one of the most fertile croplands on the globe, with several rivers pouring silt and nutrients into its soil. Because of this, the region ranks among the most densely populated in the world, despite the inherent topographical hazards of living there. The danger stems from two main factors. First, a good portion of the country barely rises above sea level. Second, its rivers (three major and several smaller ones) and the shape of its coastline combine to draw water far inland, increasing the likelihood and severity of flooding.
Storm surges strike areas like Bangladesh with particular lethality, and they cause most of the fatalities and a good portion of the property damage from storms like the Bhola Cyclone.
That just leaves one. Now, let's look at the mother of all destructive storms in recorded history.