This fact check includes links to pictures and video footage some people may find disturbing.
A post on Facebook wrongly claims that video footage of the 9/11 terror attacks on the World Trade Center in New York City shows that no planes were involved. The video has been viewed more than 20,000 times.
It shows Flight 175 hitting the South Tower, the second tower of the World Trade Center struck during the attack.
From the angle of the video, no plane can be seen hitting the tower—all that can be seen is the explosion in the immediate aftermath.
The most likely explanation for this is that the view of the plane is obscured by the tower itself. Flight 175 hit the southern-facing facade of the South Tower, meaning that anyone watching, or indeed filming, the attack from the north side may miss the moment of impact.
There are many pictures and videos available online of Flight 175 approaching and hitting the South Tower partly because so many were photographing the aftermath of the first attack. Also, as many other fact checkers and experts have written, there is ample evidence that planes were used during the attacks.
Alongside eyewitness accounts, pictures and videos of the impact itself, pieces of the aircraft were also recovered from the wreckage of the towers.