Is it an Emergency or a Disaster?

The Emergency Management Act sections 1(e) and (f) includes the following definitions:


An event that requires prompt co-ordination of action or special regulation of persons or property to protect the safety, health or welfare of people or to limit damage to property


An event that results in serious harm to the safety, health or welfare of people or in widespread damage to property

An emergency is an adverse situation requiring prompt response to save lives and protect property using existing resources and procedures. These are events that first responders (fire, police, EMS, utility companies, and parts of industry) respond to on a routine basis.

Disasters, on the other hand, are qualitatively different. They are much more serious events that threaten or cause widespread losses and damage, and disrupt social structure and essential functions. Examples of disasters include a tornado in a populated area, an incident involving dangerous goods where evacuation is required, a flash flood in an urban area, a mass casualty incident, a widespread utility outage, etc. The response to a disaster will be multi-agency and mutual aid assistance will likely be required. However, as disasters are often multi-jurisdictional, mutual aid support may be limited or, in some situations, not available. Standard operating procedures will not be adequate to manage and co-ordinate the scope and complexity of response activities. Disasters require prompt and coordinated actions by individuals with a wide range of skills and agencies using extraordinary resources and processes to counter the consequences.

Prompt and coordinated actions may be challenged by three key disaster characteristics; unknown scope, loss of communications, and impact on emergency services. Unlike most emergencies, disasters are hard to comprehend. Some of the worst-affected areas go unrecognized for hours, days and even weeks. Along with the scope being unknown, communications failures are common. Communications equipment may fail (e.g. cell lines are likely to be over-loaded or response agencies may not be able to communicate with one another because of incompatible equipment/frequencies). As well, disasters often impact the emergency services as much as anyone. For example, flooding blocking fire trucks and police cars from responding to a building fire in a flooded town or ambulances getting stuck in a snowstorm would be cases of the emergency services being affected by events.

In other words, disasters exceed the capacity of a single organization to effectively respond to the situation. An event that constitutes an emergency in one community may constitute a disaster in a different one. For example, a tornado touchdown in a sparsely populated rural area may result in an emergency response or no response. A similar tornado in a highly populated urban area or campground may result in a response involving a number of agencies, organizations and jurisdictions. 

According to Quarantelli, a leading professor in disaster research, “A disaster is not simply a large-scale accident or emergency. Ironically, to plan on the basis that there is only a difference of degree involved, is to increase the possibility that a minor emergency will be turned into a major disaster,” (1984, p. 3).

Quarantelli explains, “During disasters, organizations are often faced with a whole new set of circumstances with which they must cope. Organizations may have to (1) quickly relate to more and different groups and other organizations; (2) adjust to losing a part of their autonomy; (3) apply different performance standards; and (4) operate within a closer public and private sector interface,” (1984, p. 8). He goes on to say, “It is ill-advised to use daily performance criteria to meet the demands of disastrous situations. To function efficiently and effectively, organizations must be knowledgeable about the social environment within which they must operate during crisis situations. Furthermore, organizations must recognize that during crisis situations the environment changes quickly and drastically and that their disaster preparedness planning and response strategies must give consideration to this important fact,” (1984, p. 8).

Erik Auf der Heide, a member of the Disaster Section of the American College of Emergency Physicians and disaster researcher, summarized the general differences between emergencies and disasters as follows:



Interaction with familiar faces

Interaction with unfamiliar faces

Familiar tasks and procedures

Unfamiliar tasks and procedures

Intra-organizational coordination needed

Intra- and inter-organizational coordination needed

Roads, telephones, and facilities intact

Road may be blocked or jammed, telephones jammed or non-functional, facilities may be damaged

Communications frequencies adequate for radio traffic

Radio frequencies often overloaded

Communications primarily intra-organizational

Need for inter-organizational information sharing

Use of familiar terminology in communicating

Communication with persons who use different terminology

Need to deal mainly with local press

Hordes of national and international reporters

Management structure adequate to coordinate the number of resources involved

Resources often exceed management capacity (e.g. management structure not adequate to coordinate the number of resources involved)

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