There are many economic factors in deciding how vulnerable a city might be against a terrorist attack. Boise, the same Boise located in the state of Idaho, was the only western city to be ranked in the top ten most vulnerable cities in the United States. The cities people might perceive as more probable targets like Los Angeles and San Francisco are ranked 41 and 66 respectively. Why so low and why lower that Boise? The research is based on socioeconomics, infrastructure, and geophysical hazards. Boise is a risky city because it is located near the Lucky Peak Reservoir. This creates an opportunity for potentially flooding the city. These issues are weighted to determine how terrorists could potentially hurt the most people with the least amount of action. Essentially the report defines the opportunity costs for terrorists looking to destroy American lives.