By the FBI On the morning of September 11, 2001,19 members of al Qaeda hijacked four domestic airliners, leading to the deaths of nearly 3,000 people. What followed would become the largest investigation in FBI history, code-named PENTTBOM. The attack and crash sites were also the largest crime scenes in the Bureau’s history. At the … Continue reading Inside the FBI Investigation & First Responder 9/11-Related Illnesses