When an incident occurs that results in a large number of casualties, the typical response is for EMS to respond to the incident, triage the victims, and then transport those victims to the appropriate hospitals in as orderly and rapid a fashion as possible.

One of the major problems that are often observed with these incidents is that the hospitals rapidly become overloaded in a short period of time. This effect, known as "surge," often severely limits the ability of the hospitals to adequately treat all of the patients they receive in a timely fashion.

Recent terrorist incidents have shown that the number of victims can be significantly large, resulting in a large number of dead and injured. In the 7-7 bombing of the London subway system, 56 were killed and over 700 injured. In the Madrid bombings of the commuter train system, nearly 200 were killed and over 1700 were injured.

The primary purpose of Survivor Receiving Centers and Staging Areas (SRCSA) is to address the needs of reducing the impact of patient surge on the local hospitals while providing a transport destination to EMS of a facility other than a hospital, at least initially. The scope of the SRCSA site can be expanded depending on the level of the incident and the availability of medical personnel.

The SRCSA sites are predetermined locations that can be activated by the local emergency response system when a large scale incident occurs. These facilities are typically not used as health care facilities as they may be school gymnasiums, community centers, etc. They are facilities that can accommodate a large number of people. Once activated they are staffed with health care providers (EMTs, paramedics, nurses, physicians) to provide basic medical treatments until the patients can be treated and released or transported to an appropriate care facility.