From my understanding of the ritual of 911 the towers were the 3 pillars of the Tree of Life (don't forget building 7 which had to be brought down to complete the ritual because it had no other reason for coming down. Probably Flight 93 was intended for building 7).
The Tree of Life is the same as the cross anyway both representing nature.
In that Sherlock Holmes video the Pentagram is inverted which represents the burying (murdering) of spirit by having the other 4 arms (representing the 4 elements of the physical plane) driving the 5th arm of spirit into the ground. Holmes mentions that the sphinx is a doorway to enlightenment. So in sacrificing the 4 men there is the sacrifice of truth, nature (neter), enlightenment.
This is the same ritual used on 911 except like I said the Tree of Life instead of the cross.
Req Em Ab