Why the 911 WTC buildings could not have collapsed from the aeroplanes

From www.infowars.com and www.physics911.net

Each WTC building collapse occurred at virtually free-fall speed
(approximately 10 seconds or less).
Each building collapsed, for the most part, into its own footprint.
Virtually all the concrete (an estimated 100,000 tons in each tower) on
every floor was pulverized into a very fine dust, a phenomenon that requires
enormous energy and could not be caused by gravity alone (\\\\\\\".workers can\\\'t
even find concrete. \\\'It\\\'s all dust,\\\' [the official] said\\\\\\\").
Dust exploded horizontally for a couple hundred feet, as did debris, at the
beginning of each tower\\\'s collapse.
Collapses were total, leaving none of the massive core columns sticking up
hundreds of feet into the air.
Salvage experts were amazed at how small the debris stacks were.
The steel beams and columns came down in sections under 30 feet long and had
no signs of \\\\\\\"softening\\\\\\\"; there was little left but shorn sections of steel
and a few bits of concrete.
Photos and videos of the collapses all show \\\\\\\"demolition waves,\\\\\\\" meaning
\\\\\\\"confluent rows of small explosions\\\\\\\" along floors (blast sequences).
According to many witnesses, explosions occurred within the buildings.
Each collapse had detectable seismic vibrations suggestive of underground
explosions, similar to the 2.3 earthquake magnitude from a demolition like
the Seattle Kingdome (p. 108).
Each collapse produced molten steel identical to that generated by
explosives, resulting in \\\\\\\"hot spots\\\\\\\" that persisted for months (the two
hottest spots at WTC-2 and WTC-7 were approximately 1,350o F five days after
being continuously flooded with water, a temperature high enough to melt
aluminum (p. 70).





The criminal code requires that crime scene evidence be saved for forensic
analysis but FEMA had it destroyed before anyone could seriously investigate
it. FEMA was in position to take command because it had arrived the day
before the attacks at New York\\\'s Pier 29 to conduct a war game exercise,
\\\\\\\"Tripod II,\\\\\\\" quite a coincidence.


No steel-framed skyscraper, even engulfed in flames hour after hour, had
ever collapsed before. Suddenly, three stunning collapses occur within a few
city blocks on the same day, two allegedly hit by aircraft, the third not.


Second, severe structural damage to the WTC towers would have required fires
that were not only large but growing throughout the buildings and burning
for a considerable period of time. None of these conditions was present.
\\\\\\\"The lack of flames is an indication that the fires were small, and the
dark smoke is an indication that the fires were suffocating,\\\\\\\"