It's an interesting figure I plucked from a quick read that the building had an extimated mass of 1,000,000 tons. If contents were 70 tons per floor and we have 220 floors between the two towers, that brings the debris to 1,154,000 tons. If building 7 and the hotel and others are thrown in that is approximately 1,500,000 tons.
As of today they have said they have moved 20,000 tons of debris which means that they are only 1.33 Percent through the pile.
Damn!
It's going to be worse than that. I don't know how much of the underground they count in the tower structure, but the holes these things were built over are tremendous.
A friend of mine used to ride the train from Jersey. It came up through the basement. For months, the view of the construction site was all plywood, then one day the plywood was gone. He was astounded to find himself in riding a subway in a place that appeared to hundreds of feet above the bottom of the foundation floor. You will notice that the 300 foot antenna came down straight and the top of it is not far above ground level, and much of the tower is under it.