This two-hour documentary concentrates on the destruction of the World Trade Center's twin towers. Combining TV news tapes, interviews, still photos, and computer graphics, the program re-creates the horrible moment when a jet crashed into Tower I, followed closely by another suicide attack on Tower II. The rest of the program concerns itself with the cleanup of the rubble, the forensic evidence found during this process, an analysis of why the towers collapsed so quickly, and reactions of those nearest to "ground zero."