Despite exhaustive reports about the September 11th attacks at the World Trade Center, no one report examines the dust that poured from the skies as the buildings collapsed in as much personal and technical detail as Lioy offers here. From his own experiences examining and analyzing the dust, to his work with the various agencies involved in the aftermath of the disaster, the author puts together a compelling examination of the dust itself and the agencies, mechanisms, and people in place to deal with it.