The Rescue Stage - Disruption of the Initial Emergency Response. In the hours following a major natural disaster, the immediate rescue effort originates from the affected community itself. Local resources are quickly recruited and reorganised to suit the obvious needs at hand. In many instances, this is done on a case-by-case basis, and medical response measures may be initiated before the complete picture is considered. Within the first 24 hours the focus must remain on ensuring that the most critically ill and accessible patients receive the appropriate medical attention and care. However, with many natural disasters, the situation is further complicated by the massive disruption of critical infrastructure which prevents an appropriately organised and comprehensive medical response. Health infrastructure may be broadly defined as 'traditional lifeline systems within a given community or geographical area'. Some systems contribute directly to the health of the community such as hospitals, clinics, emergency response units, and water treatment plants. Other systems such as shelter, power, fuel, and communication, are not directly labelled as "medical care systems," but still contribute to the public health and safety of the affected populace. In the worst case scenario, the very core of the health infrastructure, the hospital, could be disrupted. A review of many of the recent major natural disasters in United States revealed that damage or collapse of a hospital is quite rare. Yet, many of the disaster response protocols which were redesigned in the 1970s account for this possibility, even though loss of power or water is more common than structural damage. Hence, most hospitals in North America are equipped with at least one, if not two, backup systems to ensure that a moderate degree of functioning can occur in even the worst situation (although in severe disasters even the backup systems have been known to fail). However, the situation is vastly different in developing countries. In many underdeveloped emergency care systems, power failures or even structural damage are a real possibility in a serious disaster. In many cases, hospitals and clinics have received no additional disaster protection over the rest of the community, leaving the area at risk to a major catastrophe. A powerful natural disaster may also directly damage other medical resources such as fire trucks and ambulance vehicles. Damage to emergency vehicles would be most disruptive in the early stage of the rescue operation as many victims seek transportation to medical centres. However, studies have shown that in large-scale disasters, many victims are brought to medical centres in taxis and private vehicles in the absence of ambulances. Thus, damage or destruction of emergency vehicles would acutely affect the critically ill patients who require specialised care at the scene or en route to a designated medical centre. Disruption of transportation routes also interfere with the initial medical emergency response. Natural disasters such as earthquakes, hurricanes, or flooding can render roads, bridges, and tunnels impassable. Inclement weather from hurricanes, cyclones, or tornadoes can ground rescue helicopters and "medi- vac" ircraft. As emergency vehicles are prevented from reaching critically ill victims, it is important to note that patients in private vehicles are equally prevented from reaching hospitals and clinics. In a study of patients caught in flooding caused by Hurricane Floyd in North Carolina in September of 1999, almost one fifth reported difficulty reaching required medical care. Just as hospitals and emergency vehicles are easily damaged or destroyed by natural disasters, so are medical supply depots and storage facilities. The damage or destruction of essential medical stores carrying medications, dressings, IV lines etc., can compound an already desperate situation. In the aftermath of any disaster, hospitals and clinics will require additional supplies in order to account for the increase in admissions. The number of victims may overwhelm the medical system's ability to provide for everyone. In addition, certain natural disasters may require specialised supplies in order to treat the presenting specific injury patterns. In some instances, a deficiency in medical supplies may contribute to a "secondary disaster" whereby victims, who would have survived with timely medical care, succumb to their injuries. Furthermore, in natural disasters, where injuries and loss of life are widespread, prompt medical care may be prevented by the loss of medical personnel. Many disaster plans require that offduty health workers are called upon in the event of a major catastrophe. A prevailing assumption is that a department may double or even triple their available work force by activating off-duty personnel. In large-scale disasters however this is not necessarily the case. A review of medical practices after the Taiwan Chi-Chi earthquake in 1999 shows that many medical personnel will only respond to the community's needs after they feel that their own family's safety and well being is assured. Combined with the loss or injury to other health care professionals, authorities in Taiwan were faced with a medical work force one half the predicted size. Finally, it was observed that many physicians and nurses that were "off-shift" at the time of the disaster were prevented from reaching hospitals and clinics due to disrupted transportation systems. A sign of a mature emergency care system is the specific development of disaster protocols and medical sub-specialities, such as trauma medicine, in order to deal with disaster injuries and challenges. Within the context of a developed emergency plan, large tertiary hospitals take a central role in providing care for victims and even act as a central point of organisation for the community as a whole. Commonly, hospitals are structurally reinforced with the forethought of the role that they will play in the disaster recovery operation. With underdeveloped emergency care systems common to developing countries, medical care in a disaster situation is usually given by physicians and health care workers who are not specifically trained in emergency medicine. In these circumstances, there is usually a diffuse response to the disaster with no centralised point of organisation. Here the hospital's role rarely extends beyond providing medical care and community or regional organisation is sporadic at best.