I felt this question offered by a reader deserves a public answer since I am sure he is not the only one who asked it.

17 November 2001 – RF

" How could the Towers at the WTC have collapsed as they did, in a straight line to the ground, by their having sustained damage to no more than three quarters of the four corners?"

The first tower to collapse experienced three major stress events while the second one received four.  These were:

1.  Initial impact and transference from aircraft to tower of lateral kinetic energy resulting from 100+ tons moving at 250-300 mph.   This event sure didn't strengthen the structural connections on that side or in the core.   I'm sure some sway was induced although this would have dissipated. (K.E. varies as the SQUARE of the velocity and so this smack was of major proportions.)

2.  Secondary explosion of part of the fuel load (in my opinion the wing tanks) during the impact event, probably 15% or so.  This event occurred at the worst possible moment, i.e. simultaneous with the deposit of a vast amount of kinetic energy into the structure from the impact.

3.  Subsequent fire of 3-5 thousand gallons of JP-8.  Total fuel capacity is around 7500 gallons so deduct for fuel consumption from takeoff to impact, plus that portion that detonated on impact.  In my 25% expert opinion the first two events would have buckled the decking of several floors with the girders providing stress/puncture points towards which much of the still unburned fuel would inevitably flow.  Add to this plenty of secondary fuel in the form of modern office equipment.  Most of the heat could not escape outwards but instead had to radiate up or down.  Steel is a much better conductor of heat than is concrete.  It therefore 'escaped' into the steel skeleton.   Large amounts of heat there had the same effect heat does when a blacksmith heats up iron before working it.

Modeling the thermal flows in the WTC towers during this period has undoubtedly already been approved for more than one Ph.D dissertation in civil engineering, physics and chemical engineering.

The second tower to collapse (first struck) also received a local seismic shock from the collapse of #1's hundreds of thousands of tons as the fourth catastrophic event.

It seems to me at least 20-30,000 tons of structure were still above the impact sites in both buildings.  Once any floor in the impact zone collapsed onto the floor below it means that next floor below (also seriously damaged from impact/explosion/fire) received a wallop from 20,000 tons accelerating straight down at 1 gravity.  Any horizontal kinetic energy  resulting from impact was long dissipated.  This means the acceleration vector was straight down.  Individual steel girders appear impregnable to us humans but they're less than toothpicks when faced with a blow from a mass of 20,000+ tons adding to its weight and speed with each floor.   Unless there had been a horizontal displacement at the moment of structural failure, there's no reason either of these buildings would have toppled over like felled trees.  Each additional floor literally gave additional weight to the argument for going straight down.  It seems to me the one assumption in this scenario is that the central core failed first.  There's good reason for believing that's where the fuel from the fuselage tanks would have pooled.

<> <> <> <>  In my opinion the more ridiculous of the WTC theories going around about more explosive charges and such are another example of Black Helicopter thought.  This kind of John Birch Society thinking is a form of denial, cowardice and also an evasion of personal responsibility.  If it were ever admitted by these types that September 11 in fact occurred largely as reported, then personal responsibility is thrust upon each individual.  This is responsibility for not having resisted the Atta's of the world and their kin to freely enter and wander around the Late Great U.S.A.    JBSers and other Black Helo types prefer instead to believe in ghosts and hobgoblins rather than believe clearly visible enemies are responsible for creating the conditions permitting September 11.  Ghosts and Hobgoblins cannot be caught or even identified with certainty.  To clearly identify a political enemy is to risk being called a coward if one then refuses to engage him.  To pursue, even with the First Amendment and the ballot box, those whose fingerprints are all over the immigration and criminal law changes that set the stage for September 11  are 'intolerance', 'racism', 'hate' and, Saints Above Preserve Us, 'anti-Semitism'.

It's much safer to believe in formless, faceless, nameless 'Insiders', than it is to put the blame where it truly is – on ourselves for believing in the "we're all equal" crap.

Robert's piece was an excellent one, better than mine was.  The one exception to the explosion observations is when we come to the most critical part of the WTC towers.  Those are the central cores.  At those points the buildings presented vertical faces to the explosions' pressure waves.  I wouldn't be surprised if a frame advance analysis of the video footage of the second impact revealed a smaller secondary wave following right behind the first large blast wave that blew out the building sides on the impact levels.  To me it would be evidence of the primary wave recoiling from the central core to the floor/ceiling and then flowing outwards.  I know covert minded folks  would probably seize on that as evidence for secondary explosions from other explosives.

In thinking this through more I can't imagine any scenario under which the impact level floors wouldn't deform.  At least two concrete decks on each tower received massive horizontal compressions where the aircraft struck.  There also HAD to be some vertical displacement upwards/downwards in the affected decks.  Here again, my imagination doesn't extend to 100 tons at 300 mph coming in without that happening.  The joints on the exterior perimeter columns on the impact side had to have debonded on impact at those levels.  I'd expect some of the joints on the columns of the perpendicular sides on the impact face of each building also failed then and there.  I picture a wedge being driven into plywood at high speed.  This leaves the central core columns and the exterior columns on the side away from impact supporting the building.

This buckling would form concave areas that would serve to puddle the fuel from ruptured tanks.  The most natural place for these concave areas to have formed is immediately adjacent to the central core.  I haven't heard any survivor stories about molten fire flooding down the stairwells in the central cores.  Therefore the fuel didn't pour through any hypothetical breaches in the cores' walls.  Nor was fire raining down the sides of the building after the initial explosions, at least that I've seen or heard.  Here again, there's been no stories about fire and brimstone falling on plazas.  This means that any unburned fuel was contained someplace up there pending combustion.

Here's a discussion of the WTC collapse by an Australian civil engineering professor.


1. Some horizontal displacement obviously occurred in the south tower to accelerate the still intact upper stories slightly to the side.  The professor (and I) think this happened because of outer perimeter failure.  Where we differ in is what progressively failed to cause this slight displacement.  He seems to be talking about failure in the face directly perpendicular to impact.  I think the columns in that face were already compromised by the impact.  I therefore think progressive failure of the columns of the outer faces' parallel to impact starting from the impact face and running back towards the opposite side is the only way to accelerate intact upper stories as a block laterally as shown in the picture.

2.  The North Tower collapse obviously followed the scenario I outlined before of central core failure followed by a pancake effect.

3.  This plan shows the arrangement of the perimeter and interior core.   http://www.civil.usyd.edu.au/wtc_plan.jpg

4.  A graphic on that page taken from the Sydney Morning Herald is very instructive about the foundation design.  The two towers shared a common foundation and sub-basements.  That common foundation would transmit the seismic shock from 450,000 impacting tons of the first tower directly into the structure of the second tower for the fourth stress event I listed.  The only event I can compare that shock to is the knock-down of the Skyway Bridge in Tampa Bay in the mid-1980s.  That happened when a freighter struck one of the two piers.

We both mentioned the kinetic energy of the aircraft strikes.  Now consider the kinetic energy generated from the first tower collapse.  Starting from 1,300 feet at least some of the mass of the first tower to fall had to reach terminal velocity of 260 mph before striking the top of the foundation structure.  Many would call this 'the ground'.  I'll be conservative and say this mass was only a paltry 25,000 tons or 5% of the total mass of the first tower.  The remainder struck at different speeds from 260 mph down to perhaps 10 mph varying with the original starting height.  People who want to work the k.e. equations could try dividing 500,000 tons into 25,000 ton increments, assign 260 mph to the first 5% and then progressively decrement the velocity of the following increments by 10 mph.  ALL of that resulting kinetic energy was transmitted directly into the common foundation underlying both towers.

It would be a greater mystery to me if the second tower hadn't collapsed after the first one fell.  I could even accept the second tower collapsing after that shock even if it hadn't been hit by the first aircraft.  Most of the discussions to date about these collapses, even by civil engineers, seem to underrate or ignore the three kinetic energy events – two aircraft crashes and the first collapse – as significant damage causes.  Once the graduate students start modeling this event I think k.e. is going to emerge as being at least as important as the fires.

And this discussion by a New Zealand civil engineer (Adobe Acrobat Reader required):


This gentleman does quantify the available k.e. from the aircraft strikes.  He considers the kinetic energy damage much more significant than the following fires.  He also doesn't factor in k.e. resulting from the first collapse.  We do know from reports that local shock was serious enough to inflict major damage on adjacent buildings across the street.  Given this result how much more damage was inflicted on the second tower to fall (sharing a common foundation) by the first falling tower?  The answer is unknowable but it's certainly greater than -0-.

Here's additional details sent by a reader.   These are extracted from a New York City emergency dispatcher's log.  Be forewarned the entire log is extremely morbid reading.


The first detail of note is this entry: "09:17:39 Mc Sts On 105 Flr ... Stairs Collapse".  Translated this means 'Male caller states on 105th floor (which tower is unspecfied) ...stairs collapse.'  The time of the entry is 43 minutes before the first collapse at 1000.  Another caller stated "09:47:15 Fc Sts 2 World Trade Centre – Flr105 – Sts Floor Underneath Her – Collapse."  'Fc' means 'female caller.  Here again the early indications of widespread structural compromise at least 13 minutes before collapse is useful evidence.  Both calls  shows the extent of structural damage early on into the event.  I think the only possible source of such damage so early was kinetic energy from the aircraft impacts.

Since F.A.E.M. is considered a 'hate site' that offends people, let me pour some more fuel on the WTC fire I've started.  I want to further offend the Black Helicopter True Believers who style themselves as 'patriots'.  Many of these people, as exemplified by the late alcoholic Bill Cooper, are also Area 51 and UFO True Believers, too.  These are the same ones who attend Barry Chamish (an Israeli Jew) lectures sponsored by Joel Skousen.  At these events Chamish also lectures on John Birch themes interwoven with his other specialty of UFO-logy aka U-FOOL-OLOGY.

There is no bottom to their craven gullibility.  This was demonstrated in the 1990s by the Super Patriots residing in the former southwestern territories of the Late Great U.S.A. These lands have since been ceded to Mexico everywhere except on the cartographers' maps.  The Immigration Invasion that detached these territories really gathered headway during the 1990s.   Now at this same time what 'sovereignty' issue was #1 on the Southwestern Super Patriots' list?

Yes.  Memories are returning now that I mention this, aren't they?  The crisis was secret German Luftwaffe bases in Arizona!  THERE WAS THE REAL THREAT!  It always amused me that the proponents of that red herring ignored the Luftwaffe anti-aircraft training detachment located at the U.S. Army Air Defense Artillery School at Fort Bliss.  I have no idea why.  At that time that section of Fort Bliss was on a publicly accessible part of the reservation there in El Paso.  They could have spiced up the jazz with pictures of signs in German and personnel in German uniform.  In contrast the krauts' aircraft squadron was on a closed air force base.  Probably this is why a German training squadron was popularized instead.  The small scale of the visible Fort Bliss detachment, located just down the street from the post museum, would have disillusioned too many.  Delirious imagination (delirium tremens in Cooper's case) had free reign with an inaccessible location similar to Area 51.

Meanwhile beaners by the million were pouring into these nit-wits' living space right in front of their eyes and what did they find to occupy their 'patriotic' energies?  A non-event over minuscule German training detachments is what seized them.    I have commented on this mental escapist mechanism before and will repeat now:  that kind of thinking is ultimately just cowardice and a justification for abdicating one's real civic duties.  People who behave that way DESERVE to lose their country.