Top Officials 3 (TOPOFF 3) is the most comprehensive terrorism response exercise ever conducted in the United States. Sponsored by the U.S. Department of Homeland Security's (DHS) Office of State and Local Government Coordination and Preparedness (SLGCP), TOPOFF 3 is the third exercise in the TOPOFF Exercise Series, a congressionally mandated exercise program. The exercise is designed to strengthen the nation's capacity to prevent, protect against, respond to, and recover from terrorist attacks involving weapons of mass destruction (WMDs). Joining the Department of Homeland Security and other federal agencies in this important effort are the states of Connecticut and New Jersey, as well as two international partners, the United Kingdom and Canada. These countries will conduct simultaneous, related exercises.
Dept. of Homeland Security: http://www.dhs.gov/