The September 11, 2001 terrorist attacks on the World Trade Center, perhaps the worst episode in the history of New York City, also created a significant environmental health emergency. This February 2002 report lays out the facts, as best as we know them at this point, regarding both the environmental impacts of the attacks and the response of government officials to the ensuing environmental emergency. It also sets forth recommendations for improving New York's readiness for future environmental health emergencies.