The National Incident Management System (NIMS) was an emergency response system that was designed to ensure that proper coordination and communication was established during the event of a crisis. Possible disasters can include an act of terrorism, an urban fire, floods, nuclear disasters, earthquakes, power storms such as hurricanes and typhoons, war-related incidents, etc. The NIMS system was established nationwide and modeled after the initial Incident Command System (ICS) that was created after devastating wildfires in the state of California. Not only does the emergency response system improve communication and coordination, but it was also designed as a means by which mitigation and preparedness can help prevent or lessen the effects of a man-made or natural disaster.

Mitigation:
Mitigation in emergency management means the steps taken to prevent all possible hazards that may lead towards a disaster. The mitigation phase of emergency management is unique because it focuses on long-term tasks that are effective at reducing or eliminating any risk of a disaster from occurring. Mitigation is part of four phases of emergency management:

(1) Mitigation; (2) Preparedness; (3) Response; (4) Recovery.

After the recovery phase, mitigation may begin again as a part of the recovery process.

Mitigation can come in the form of structural or non-structural. An example of structural mitigation is the building of a damn to prevent floods from occurring in an area that may be vulnerable to floods during heavy storms. Non-structural mitigation can involve any type of legislation, insurance, or other planning. While not always suitable, mitigation is the most cost-effective way to prevent and lessen the effects of disasters. Structural mitigation may have harmful effects on the environment if not used properly and it provides rules and enforcement during the event of a crisis, such as regulations on evacuations.

The first step in mitigation is to identify risks. This is usually done by finding a potential hazard and then examining it to determine the chances of it causing a disaster and who is vulnerable to the disaster. For example, if there is a catastrophic earthquake, but it occurs in the middle of the desert where nobody lives, then there is no risk involved.

Preparedness:
Another important part of emergency management is preparedness. This usually involves having a plan in case a disaster does happen. This phase comes before an emergency response and is usually vital in reducing the dangers during the emergency response process. There are several aspects of preparation that is covered to ensure that a disaster is handled properly:

* Plans of communication are defined and universal terminology is established;
* Emergency response teams are trained to be quick and coordinated;
* Development of public emergency response services for communication and spread of information;
* Stockpiling important supplies and organization to ensure there is proper access to them;
* Creation of emergency response volunteers who are properly trained among the population.

Preparedness is also understanding and evaluating a casualty prediction. This is basically estimating how many deaths may occur if a certain disaster would happen in a given location. This will give an idea of what kind of supplies and how much is needed, and which emergency response protocol needs to be used.