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Homeland Security

Executive Summaries


The Homeland Security Council (HSC) - in partnership with the Department of Homeland Security (DHS), the federal interagency, and state and local homeland security agencies - has developed fifteen all-hazards planning scenarios for use in national, federal, state, and local homeland security preparedness activities. These scenarios are designed to be the foundational structure for the development of national preparedness standards from which homeland security capabilities can be measured. While these scenarios reflect a rigorous analytical effort by federal, state, and local homeland security experts, it is recognized that refinement and revision over time may be necessary to ensure the scenarios remain accurate, represent the evolving all-hazards threat picture, and embody the capabilities necessary to respond to domestic incidents.

This document includes executive summaries for the fifteen scenarios, and a separate document contains the complete scenario text.

General Considerations for the Scenarios:

The scenarios have been developed in a way that allows them to be adapted to local conditions throughout the country. Although certain areas have special concerns - continuity of government in Washington, D.C.; viability of financial markets in New York; and trade and commerce in other major cities - every part of the country is vulnerable to one or more major hazards.

Because the attacks could be caused by foreign terrorists; domestic radical groups; statesponsored adversaries; or in some cases, disgruntled employees, the perpetrator has been named, the Universal Adversary (UA). The focus of the scenarios is on response capabilities and needs, not threat-based prevention activities.

Since these scenarios were compiled to be the minimum number necessary to test the range of response capabilities and resources, other hazards were inevitably omitted. Examples of other potentially high-impact scenarios include nuclear power plant incidents1, industrial and transportation accidents, and frequently occurring natural disasters. These either have welldeveloped and tested response plans, and/or the response would be a subset of the requirements for scenarios contained in this set.

Detailed assumptions for each scenario are provided in the full-text of this document but are not provided in this executive summary.

Intelligence Disclaimer -

While the intelligence picture developed as part of each scenario generally reflects suspected terrorist capabilities and known tradecraft, the Federal Bureau of Investigation (FBI) is unaware of any credible intelligence that indicates that such an attack is being planned, or that the agents or devices in question are in possession of any known terrorist group.

Ranking of Scenarios -

Various schemes have been used in the past to rank scenarios based on probability, number of casualties, extent of property damage, economic impact, and social disruption. Because the scenarios in this set were developed to test the full range of response capabilities and resources - and to assist federal, state, and local governments as well as the private sector in preparedness - they have not been ranked. Each jurisdiction or organization should apply its own priorities, based on its responsibilities within the domestic incident management structure.

Multiple Events -

There is a high probability that multiple incidents will occur simultaneously. When scoping resource requirements, organizations should always consider the need to respond to multiple incidents of the same type and multiple incidents of different types, at either the same or other geographic locations. These incidents will invariably require the coordination and cooperation of homeland security response organizations across multiple regional, state, and local jurisdictions.

The Homeland Security Advisory System -

The scenarios do not specify changes in the levels of the Homeland Security Advisory System (HSAS). However, in all scenarios other than natural disasters, it is anticipated that the alert level would increase. This increases the nation's ability to respond to the current attack, reduces the vulnerability to future attacks, and helps citizens prepare to protect themselves. At higher alert levels, the HSAS has increased resource demands and can also have national economic impacts.

The "Worried Well" -

In most incidents, citizens will seek medical treatment even though they may not be injured by the incident. For example, in the World Trade Center incident on 9/11/01, the uninjured who sought medical treatment was approximately fifteen times the number of people who presented for medical treatment due to smoke inhalation; and in the Tokyo subway attack it was five times the number of victims experiencing chemical poisoning. For planning purposes, most experts calculate a ratio of ten-to-one.

Infrastructure Impact -

The effect of disasters on national, state, and local transportation, communication, medical, and utility infrastructure will have a considerable effect on response strategies. As on 9/11, when the entire civilian air transportation system and much of the national telecommunications system were shut down or disabled, a terrorist incident may have repercussions that affect critical infrastructures necessary for coherent emergency response. These critical networks must be layered and properly coordinated across both civilian and military sectors to ensure the continuity of critical infrastructure support for responding jurisdictions.

Economic Impact -

Catastrophic disasters, depending upon the type, scope, and magnitude of the disaster incident, could threaten the economic sustainability of the communities affected and may cause severe disruption and long-term economic damage. Extreme disaster incidents can generate cascading economic situations extending outside the immediate community. Even in moderate disasters, of all businesses that close following a disaster, more than 43% never reopen, and an additional 29% close permanently within 2 years2. The American Planning Association notes, "Economic recovery is quite likely the most serious issue facing most communities in the post-disaster period, and almost certainly the central issue in every major disaster."3

Environmental Impact -

Catastrophic natural and manmade disasters and terrorist attacks can result in extreme environmental impacts that challenge government and community recovery time. Long after the emergency phase subsides, contamination from disasters may remain, consisting of chemical, biological, or radiological materials. While decontamination technologies may be well established for some types of contamination, others are only moderately effective - some contaminants, especially radionuclides, are very difficult and costly to remediate. While some decontamination techniques may be effective in small sites, these techniques may not be suited for decontaminating expansive areas of varying physical characteristics. Evacuation and relocation during cleanup and restoration activities can result in significant business loss and failure, leading to local and regional economic downturn. In addition, agricultural and industrial products from an area contaminated, or thought to be contaminated, can generate impacts that extend within a region and beyond.

International Dimensions -

It is important to underline the significant international dimensions that arise in connection with some of the more damaging and devastating scenarios in which significant loss of life and property, together with the possibility of foreign-directed terrorism, are involved. First, there is the hemispheric dimension of effects on U.S. relations with Canada and Mexico in terms of cross-border trade, transit, law enforcement coordination, and other key issues. Second, there is the immediate treaty connection the United States has with other North Atlantic Treaty Organization (NATO) allies if the United States comes under attack. Third, there is the significant lobbying the United States will undertake at the United Nations (UN) to articulate American needs and interests. In addition to humanitarian and law enforcement assistance from NATO allies, other nations may contribute special equipment in order to meet other necessities. Instances where a disaster or terrorist attack has disrupted major urban centers and international transit/trade routes through U.S. cities will typically require significant coordination with the State Department to ensure all economic, trade, commercial, consular, military cooperative, and humanitarian assistance is rendered as needed.

The State Department plays several key roles in post-disaster situations. It assists foreign citizens affected by the incident. It identifies the specific needs of affected U.S. areas where foreign offers of assistance can be mediated and arranged. Moreover, in cases where explicit terrorist activities may have occurred, the State Department is a leader in facilitating the investigations abroad needed to determine the origins of the attack, in pursuing diplomatic and follow-up policies related to finding the guilty parties abroad, and in rendering coordinated international assistance to U.S. recovery efforts.

1 A severe incident at a nuclear power plant, whether or not it is terrorist-initiated, could result in a release of radioactive materials to the environment with adverse consequences to public health. Scenarios for such severe incidents have not been included in this scenario set because: (a) current federal regulations from the Nuclear Regulatory Commission and the DHS Federal Emergency Management Agency (FEMA) mandate robust emergency planning and preparedness for each nuclear plant to include the full range of response organizations; and (b) scenarios for nuclear plants cannot be generically extrapolated to other types of facilities (e.g., chemical plants).

2 Institute for Business and Home Safety, at

3 Planning for Post-Disaster Recovery and Reconstruction (1998), American Planning Association-Federal Emergency Management Agency, Planning Advisory Service Report No. 483/484, p. 53.

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