September 12, 2001-September 2005: Weight of WTC Towers in Dispute

Ronald Hamburger, a member of NIST’s WTC team and advocate of the ‘piledriver’ theory. [Source: National Council of Structural Engineers' Associations]After 9/11, the scientists investigating the WTC collapse give very different figures for the buildings’ weight. Some sources say that each building weighed 500,000 tons. For example, MIT professor Thomas Eager writes, “The total weight of each tower was about 500,000 t.” [Scientific American, 10/9/2001; Eagar and Musso, 12/2001; Frank Greening, 2/16/2006, pp. 23 ; PBS, 8/2006] However, the National Institute of Standards and Technology (NIST) states that the buildings weighed only 250,000 tons each. [National Institute of Standards and Technology, 9/2005, pp. 32 ] One theory explaining the building’s total collapse is that the upper section acts as a “piledriver” and smashes through the floors below it. [BBC, 9/13/2001; Stanford Report, 12/5/2001] The heavier the upper block above the impact zone, the more likely it is to be able to destroy the other floors as it falls.