Natural disasters are further classified by size and impact on people (called catastrophic hazards) and amount of time (called rapid or slow onset hazards).  As we discuss the health and safety issues of natural hazards, there are three different consequences of event: Primary Effect – The primary effect of a disaster is the result of the incident itself. Primary effects include wind and rain damage from a hurricane or burned building from a wildfire. Secondary Effect – Secondary effects happen as a result of the primary effect, such as the loss of electricity and running water from a hurricane or fires igniting after an earthquake. Tertiary Effect – Tertiary effects are the long-term impacts that result from the primary effect.