Its bad to be caught off guard. Especially when chemical and biological weapons are involved. So from April 4 to April 8, participants in the Top Officials 3 (TopOff 3) program, a congressionally mandated counterterrorism exercise for high-level officials, prepared. Designed to strengthen the nations capacity to prevent, prepare for, respond to and recover from an attack involving weapons of mass destruction, TopOff 3 is the most comprehensive terrorism response exercise ever conducted in the United States. In New Jersey and Connecticut, roughly 10,000 officials from more than 275 government and private-sector organizations participated in the drill. DHSSecretary Michael Chertoff was involved, as well as other officials in Washington, D.C., Canada and the United Kingdom. Participants spent two years planning and preparing for the week of full-scale exercises. Experts in weapons, war games, law enforcement, intelligence and international terrorism developed the scenarios. The drills were held in New London, Conn., and Union and Middlesex counties in New Jersey. Eighteen months in advance, states were alerted to the type of attack theyd face, but they were not given all the details. Connecticut TopOff 3 coordinator Robert Ross says the biggest lesson learned was the need for a more unified response to a crisis. When officials arrive on an incident scene, they should coordinate their efforts with other agencies and not just act on their own. The first TopOff exercises were held in May 2000 in Denver and in New Hampshire. TopOff 2 took place in Seattle and Chicago during May 2003. Arizona, Oregon and Guam will be the locations for the spring 2007 TopOff 4.