A part of one of the 9-11 panes was discovered between a building's wall and the adjacent mosque in Manhattan 12 years after the 9-11 attack.
The strange thing was there was a piece of bull rope around the item as it was discovered.
1. OK, it could have been seen there and someone tried to get it out which was was very tough to do since it weighed 250 LBs.
2. Or it could have been dropped there? Who would drop it there? Someone who wanted to put a part of a real commercial plan there to prove that it was a commercial aircraft that crashjed on 9-11 (as opposed to a military version of the airliner).
3. Or someone discovered that it was from the military version of the airliner and they wanted to remove it.
We never heard anything more after it was discovered, another classic black hole investigation by the FBI.
My money is on item #3.
Picture of part trapped between walls in NYC April 2013