Looking at the FEMA and NIST investigations themselves, we  see that there are problems:


Just a few  examples:


The FEMA investigation found evidence of a eutectic reaction in some of the steel members: the upshot: 8 inch  steel columns were vaporized to razor sharp thickness. There was no follow-up investigation.


NIST’s scenario suggests that the aircraft collision destroyed several floors of each of the twin towers, creating an upper and lower block, and that the smaller upper block out crushed the larger lower block.


NIST only simulated the collapse of the upper stories of the twin towers; to the point of what they call being “poised for collapse,”


They only assumed, but never proved, that the upper block crushed the lower block. No momentum transfer analysis of the upper block into the lower block was provided.


It turns out in fact, that a careful video analysis of the collapsing upper floors show that there was no "upper block":  it disintegrated prior to its collapse onto the lower block


NIST admits “ we are unable to provide a full explanation of the total collapse.”

( NIST Response to Scholars for 911 Truth and Justice’s  Request For Correction)


According to The NFPA (National Fire Protection Association) 921 Guide for Fire and Explosion investigation, looking for explosives residues is the standard procedure for fire and explosion investigations, yet NIST did not look for any such residues.


The engineering community (outside A&E911truth.org) has also raised questions about the results of the NIST WTC investigation:  



James Quintiere, Ph.D., one of the world’s leading fire science researchers and safety engineers, and former Chief of the Fire Science Division  at NIST, has called for an independent review of NIST’s investigation.



The popular British construction industry magazine New Civil Engineer International (NCEI) notes:


Controversy still surrounds the exact collapse mechanism of the Twin Towers, despite three years of detailed investigation by the National Institute of Standards & Technology (NIST) team.  Some engineers believe the collapse was influenced by factors other than the fires caused by burning aviation fuel which weakened vital structural steel elements. And they have accused NIST of repeatedly changing its explanation of the collapse mechanism….”In this latest version, the hat trusses on top of the towers play a crucial role in the redistribution of stresses after the impact,” one leading US structural engineer told NCE in New York  “In earlier versions they are hardly mentioned.”


Regarding the analysis used to bring the towers to the point of being “poised for collapse,” NCEI notes: “NIST had obviously devoted enormous resources to the development of the impact and fire models…The software used has been pushed to new limits, and there have been a lot of simplifications, extrapolations and judgment calls.” The same article notes NIST is “refusing to show computer visualizations of the collapse of the Twin Towers despite calls from leading structural and fire engineers…Visualizations of collapse mechanisms are routinely used to validate the type of finite element analysis model used by the investigators.”