Transcript for 747 Cargo Plane Crash in Afghanistan: Cause Determined
Thank you, so much, josh. Some new information that has emerged overnight about what really caused the terrifying crash of the 747 cargo plane in afghanistan. The disaster killed every person on board. From the beginning, there was a speculation of a problem in the way the plane was weighted. Martha raddatz has the latest. Reporter: Seven crew members on board that plane. We won't show you the moment of impact. It was carrying multion the armored vehicles. Mraps. From day one it was thought they were part of bringing the plane down. A stunning and horrifying image. Shot from a dash cam. The nose pointed steeply toward the sky and suddenly pitching down. This morning, with assistance from the ntsb, the afghans are concluding that the big armored vehicles on board, likely broke loose and slid to the back of the plane. I think that the load they had these machinery floating inside the aircraft. They might have moved or some of the locks broken and caused the vehicles to move back. Reporter: Investigators say they found broken buckles that were supposed to hold the mraps in place. We knew from the first day the planes were loaded with the vehicles weighing between 12 and 18 tons. From the video, our abc news consultant said then it appeared the vehicles broke free. The nose is up so far because perhaps cargo has shifted to the back and pushed the tail down and the nose up. At this point, the pilots don't have the control authority to push the nose down. Reporter: In fact, this morning, the afghan officials said the last word on the flight recorder was weight. No one knows for sure whether that was a reference to the heavy cargo or the pilot trying to figure out what he could possibly do to keep the airplane in the sky. But with that enormous weight shift at the critical moments at takeoff, it meant there was nothing the pilot could have done to save the plane and the crew members on board. Elizabeth? Now the focus on how the vehicles secured.
This transcript has been automatically generated and may not be 100% accurate.