October 2002-October 2005: NIST Adjusts Input Data so Computer Simulations of WTC Result in Collapses

During the course of its three-year investigation of the World Trade Center collapses, the National Institute of Standards and Technology (NIST) performs computer simulations of the behavior of each WTC tower on 9/11. In its final report, released in October 2005 (see October 26, 2005), it will describe having determined which variables most affected the outcome of its various simulations. Then, “[f]or each of the most influential variables, a central or middle value and reasonable high and low values were identified.” However, “[u]pon a preliminary examination of the middle cases, it became clear that the towers would likely remain standing. The less severe cases were discarded after the aircraft impact results were compared to observed events. The middle cases… were discarded after the structural response analysis of major subsystems were compared to observed events.” Therefore, the “more severe case… was used for the global analysis of each tower.” But, to “the extent that the simulations deviated from the photographic evidence or eyewitness reports, the investigators adjusted the input, but only within the range of physical reality.” [National Institute of Standards and Technology, 9/2005, pp. 143-144]