Risk management is defined as a systematic and analytical process to consider the likelihood that a threat will endanger assets, such as individuals, infrastructures, utilities, communications, and emergency services and to identify actions that will reduce the risk and mitigate the consequences of an attack. While risks generally cannot be eliminated, they can be reduced by enhancing protection from validated and credible threats. Although many threats are possible, some are more likely to occur than others. All assets are not equally critical. An effective risk management program includes three important elements: a threat assessment, a vulnerability assessment, and a criticality assessment. A threat assessment identifies and evaluates threats based upon various factors. It is never known whether every threat has been identified, therefore vulnerability assessments and criticality assessments become essential to better prepare for terrorist threats and attacks. A vulnerability assessment identifies weaknesses that may be exploited and suggests options to eliminate or mitigate those weaknesses. A criticality assessment identifies and evaluates an organization’s assets based upon a variety of factors, including the importance of its mission or functions, whether people are at risk, or the significance of a structure or system. The major challenges in applying an accepted threat and risk assessment process are security issues, the lack of specificity, and the complexity and magnitude of a large city. The simple qualitative risk-assessment process involves five steps: (1) determine the value of assets and judge the consequences of loss; (2) identify threats and pair with assets; (3) identify asset vulnerabilities; (4) determine risk through scenarios; and (5) identify actions, as necessary, that lead to risk reduction.