Understanding of what constitutes a disaster has altered over time in accordance with changing notions of cause and effects. The “Black Death” which swept Europe was then regarded as inevitable, with some religious groups descibing it as “An Act of God”. Perception of disaster has moved from an emphasis on the physical effects of an event, such as cyclone, fire or chemical explosion, to a perception that the extent of deleterious effects is predominately a social issue.

“Sociologically, a disaster is an event, located in time and space, that produces conditions whereby the continuity of the structure and processes of social units becomes problematic. Disaster agents may differ as to their cause, frequency, controllability, speed and onset, length of forewarning, duration, scope of impact and destructive potential” (Dynes, 1975).