An initial local failure occurred at the lower floors (below floor 13) of the building due to fire and/or debris induced structural damage of a critical column (the initiating event) which supported a large span floor bay with an area of about 2,000 square feet;
.......then it would have been a very easy controlled demolition to carry out, and it is unlikely to silence any of us conspiracy theorists. Roll on "the end of the year", when the final report will be released.


