So which hazards are most threatening to a population?
It is either scale, surprise or extended period that creates the bigger threats to communities.
The size of flood or Earthquake or Tsunami
The lack of warning of the earthquake or landslide or tornado
The duration of flooding or a of storm or of a drought
Or the complex nature of the event
All of these can breach the threshold of prepared coping mechanisms
In the short term is has always been the Earthquake within a concentrated area that causes biggest devastation not only to infrastructure but to the population also. The less frequent Tsunami can equally cause high casualties but over a larger limited area of a coastline.