Investigation into Alleged Fifth 9/11 Plane Continues Amid Terrorist Suspicions

A new documentary, "TMZ Investigates: 9/11: The Fifth Plane," claims that United Airlines Flight 23 was intended to be the fifth plane used in the 9/11 terrorist attack. The documentary alleges that suspicious activities occurred on the flight, including the discovery of two box cutters on a neighboring plane and odd behavior from passengers in first class. The pilot of Flight 23 believes that the two box cutters were meant for his plane and that it was intended to be used as a weapon of mass destruction. The FBI declined to comment on the claims made in the documentary.