Earthquakes

Location - For example, areas around the Pacific Ocean in particular are susceptible to tectonic hazards due to their location near the Pacific Ring of Fire. Location also plays a large role in determining climate.
Population - A larger population will mean more people are vulnerable to natural hazards.
Nature of settlements and the buildings within - durability of buildings within a settlement will often determine the amount of damage after an earthquake or eruption.
Telecommunications - though lines may be damaged in an event, good telecommunication networks in an area can affect responses to an event.