The all-new special TMZ Investigates: 9/11: The Fifth Plane investigates what could have been a fifth plane being targeted by hijackers on 9/11, with interviews from the flight attendants, the pilot and others who believe their plane may have become a weapon of mass destruction.

There were a series of suspicious and alarming activities on United Flight 23, a 767 that was scheduled to take off at 9 AM from JFK en route to LAX on September 11, 2001. The suspicions caught the interest of the FBI, which interviewed the flight crew and proceeded to take them to a secret lineup to see if they could identify four passengers who were in first class.

During that fateful morning, United Flight 23 was called back from the runway after the World Trade Center was hit, and when it returned to the gate, the plane was fully evacuated and locked. However, workers on the ground noticed two uniformed people roaming the cabin 20 minutes after the door was locked, and when authorities boarded the plane to investigate, the hatch that led from the belly of the plane into the passenger cabin was mysteriously open.

The pilot states he was told by a United official that boxcutters were discovered in first class seat pockets on the plane parked directly next to Flight 23 — the tail number was just one digit off — and the pilot believes someone on the ground mistakenly put the boxcutters on the wrong plane.

The special also includes interviews with the United dispatcher, a member of the 9/11 Commission and a former member of Congress who represented Manhattan on 9/11.

The special premieres Monday, March 20 (9:01-10:00PM ET/PT) on FOX.

TMZ Investigates: 9/11: The Fifth Plane is executive-produced by Harvey Levin, Charles Latibeaudiere, Ryan Regan, Jess Fusco with co-executive producer Susan Favre. Viewers can watch with On Demand, FOX NOW, Hulu and FOX Entertainment’s streaming platform, Tubi. On Demand episodes are available for customers of Cox Contour TV, DIRECTV, DIRECTV Stream, DISH, fuboTV, Hulu + Live TV, Optimum, Spectrum, Verizon FiOS, XFINITY, YouTube TV and many more.

FACEBOOK: @RealityClubFOX TWITTER: @RealityClubFOX INSTAGRAM: @RealityClubFOX

-FOX-