Reply #157: Most people who claim the WTC fell "naturally"...

[Kevin Fenton]

... satisfy themselves with doubling the actual numbers once, but you actually manage to double them twice.

You write: "The Mass of the structure of each #1 and #2 WTC is given at approximately 500000 tons."
Well, it might be given on the internet, but the figure is incorrect. You can find the real figure on page 32 of the NIST report (page 82 of the .pdf):
"With no warning that could be discerned in WTC 1, WTC 2 collapsed. The shudder as the more than 250,000 tons of steel, conrete and furnishings hit the ground was felt well beyong the site."
http://wtc.nist.gov/NISTNCSTAR1CollapseofTowers.pdf

You then double your ficticious number again without a valid reason.
If we take the central impact floors as 96 and 81 and pretend the weight of each floor was equal at 2,270 tons (250,000 tons divided by 110, although actually the upper floors weighed less), then we have 31,780 tons above the central impact floor in WTC 1 and 65,830 tons above the central impact floor in WTC 2.

You wrote: "When the aircraft hit each building, they did considerable damage to the load-bearing walls on the exterior of the building,"
Each tower had 236 perimeter columns. Name one floor where more than 18 were severed.
The gravity load was divided more or less equally between the core and the perimeter. The severed columns in the perimeter accounted for 7.6% of WTC 1's gravity load-bearing capacity and 7.1% of WTC 2's gravity load-bearing capacity. Given that the building had a safety factor of at least 3, I wouldn't call that "significant".

If you want to claim the asymetric nature of the damage was the killer, then please first have a brief look at how NIST claims the hat truss (one of the 4 main structural elements in the building) redistributed the loads after the impacts.

"Their fuel burned along with the contents of the structure (a
considerable source of fuel)"
Well, that's not quite what NIST says:
"The initial jet fuel fires themselves lasted at most a few minutes." (p. 183/233).

Care to try again?