The Skeptics Society & Skeptic magazine

9/11 and the Science
of Controlled Demolitions

by Chris Mohr

With the tenth anniversary of the 9/11 attacks upon us, a group of 9/11 conspiracists are working hard to publicize their claims of scientific validity to the conjecture that the World Trade Center buildings were destroyed through controlled demolition. The architect Richard Gage is the founder of the nonprofit organization Architects & Engineers for 9/11 Truth, which focuses on the controlled demolition theory. So outraged was I by the Bush administration’s justification for the war in Iraq based on faulty WMD intelligence information that I initially thought that Gage might be on to something, until I examined his science carefully and engaged him in a spirited debate on March 6, 2011 in front of 250 people in Boulder, Colorado. (Listen to the debate audio.) The video of that debate is not being released (his own website admitted that twice as many people changed their minds in my direction as his during the debate), so I created 20 short videos on YouTube that present detailed rebuttals of each of Gage’s claims.

• WATCH PLAYLIST 1: Twin Towers (duration 2:09:29)
• WATCH PLAYLIST 2: Building 7 (duration 1:35:48)

What follows is a brief summary of Gage’s points and my rebuttals to them.

United Airlines Flight 175 crashes into the south tower of the World Trace Center complex in New York City during the September 11 attacks. A controlled demolition couldn’t have been created at the same site where a plane impact and a raging jet fuel fire would have obliterated the demolition rigging. (Click any image in this article to enlarge it.)

1 EXPLOSIVE DEVICES WERE CAREFULLY AND SECRETLY PLANTED IN THE WTC BUILDINGS. You cannot secretly prepare a controlled demolition of the two World Trade Center buildings containing 50,000 workers, plus extensive security systems and guards, working round the clock, without anyone noticing anything unusual. Instead, we should accept at face value what we all witnessed: two massive jets that slammed into the buildings, damaging the structures and setting off raging fires and igniting more than 40,000 square feet of office space per floor in a matter of seconds, igniting furniture, carpeting, desks, paper, etc. You cannot control the area around such a raging fire to start a demolition.¹

Plumes of smoke billow from the World Trade Center towers in New York City after a Boeing 767 hits each tower during the September 11 attacks. Was architect and 9/11 conspiracy theorist Richard Gage kidding when he said the fires in the Towers were almost out shortly before their collapses?

2 NO TALL STEEL FRAME BUILDING EVER COLLAPSED BEFORE 9/11 DUE TO FIRE. Though it is true that no tall steel frame buildings ever collapsed due to fire alone prior to 9/11, since then, other tall steel framed buildings have. On May 13, 2008, a large part of the tall concrete-reinforced steel architecture tower at the Delft University of Technology in the Netherlands caught fire and thereafter had a very fast, nearly straight-down collapse mostly into its own footprint. Gravity increases the force of a falling object by a factor of 30 for a single collapsing floor, and collapsing buildings have nowhere to go but straight down. Other types of steel frame structures have collapsed due to fire.²

3 WHAT ABOUT THE ALMOST FREE-FALL COLLAPSE OF THE TWIN TOWERS? The key is the “almost” modifier. If I told you I was making almost $100,000 and you found out I was making only $67,000, you’d say I was exaggerating. So stop exaggerating the collapse speed of the WTC Towers! The 80,000 tons of structural steel slowed down the collapses of the Twin Towers to about ⅔ (two-thirds) of free-fall.³ And the core collapsed at about 40% of free-fall speed, coming down last.⁴ According to Richard Gage: “To bring a building symmetrically down, what we have to do is remove the core columns.” But on 9/11 the stronger core columns came down last, which violates this supposed most fundamental rule of controlled demolition.

On 9/11, massive steel objects smashed into neighboring buildings accompanied by winds at speeds up to 482mph. Shown here a heavy beam from the World Trade Center hangs from a nearby building.

4 WHAT ABOUT THOSE EXPLOSIVE SQUIBS TWENTY STORIES BELOW THE COLLAPSE POINT, AND THOSE HEAVY METAL OBJECTS FLYING HUNDREDS OF FEET THROUGH THE AIR? During the collapse, one half million cubic feet of air per floor was pushed outwards at the rate of twelve floors per second, creating a “hurricane wind” in the building as reported by survivors, and blowing out windows, and with them the smoke from the fires and other objects.⁵

5 WHAT ABOUT THOSE BILLIONS OF IRON MICROSPHERES THAT R.J. LEE FOUND IN A DUST ANALYSIS THAT PROVES THE THEORY THAT THE IRON IN THE BUILDINGS WAS MELTED BY THERMITE? Thermite would leave tons of formerly melted iron blobs, not just microspheres. But in the 1970s, while workers welded thousands of steel beams together, hot microspheres were splattered everywhere. Concrete has fly ash in it, and I have a photo of iron-rich spheres in Tolk fly ash in my YouTube video response. Even if the microspheres were created in the fires on 9/11, the R.J. Lee dust study said, “Considering the high temperatures reached during the destruction of the WTC … Iron-rich spheres … would be expected to be present in the Dust.”⁶

6 WHAT ABOUT THE SULFIDIZED STEEL THAT MELTED AND THAT FEMA FOUND BUT WHICH NIST IGNORED IN THEIR REPORT? NIST didn’t ignore it. Jonathan Barnett at FEMA studied two pieces of sulfidized steel, which is not enough to explain the collapse. NIST determined that neither piece came from a supporting column in the collapse zone so it couldn’t have contributed to the collapse.⁷ Sulfidized steel melts at temperatures 1000° lower than regular steel so it could have “melted” in a regular office fire. And the “intergranular melting” FEMA discovered is not like melting as we know it anyway; it’s more like corrosion on an almost microscopic scale occurring along the boundaries between the crystals or grains of a metal. The technical description for what happened is “intergranular melting, high temperature corrosion via sulphidation, oxidation, and decarburisation leading to a liquid Iron Oxide Suflur mix from grain boundary melting.” And while Jonathan Barnett would like to see more research on this, he does not support the controlled demolition theory.

7 WHAT ABOUT ALL THOSE UNIGNITED NANOTHERMITES THEY FOUND IN THE DUST SAMPLES IN THAT EXPERIMENT? Niels Harritt, Steven Jones and other 9/11 controlled demolition theorists claim to have found nanothermite particles in dust samples from the World Trade Center. They made sure the dust samples were untainted, and used advanced instruments to measure what happened when these tiny red-grey chips were heated up.

Thermites reach temperatures of around 4500° and have their own oxygen supply when they burn, so they can burn underwater. Harritt, Jones, et. al. therefore should have heated up the chips in a nitrogen or argon atmosphere to eliminate the possibility that regular hydrocarbons were burning. They also failed to take the carbon-based products out of the mix, so what we may well be seeing is some kind of carbon-based product burning in oxygen. They compared the sudden energy spike of their burning chips with the spikes of known nanothermites, and found that their chips ignited at around 150° C. lower than the known nanothermites, and the energy release was off between their chips and the nanothermites by a factor of at least two. Yet they called this a match for nanothermite!

Attempts to independently replicate this experiment have been dismal. Mark Basile, who appeared in the acknowledgments of the original study, burned the chips in air, replicating the error of the original experiment and not even measuring the energy released. A chemist named Frédéric Henry-Couannier got another dust sample from the original experimenters and wrote, “Eventually the presence of nanothermite could not be confirmed.” The R.J. Lee Company did a 2003 study on the dust and didn’t find thermitic material.

Major fires on most floors of World Trade Centre Building 7 were much worse on the side facing the Twin Towers’ collapses.

8 WHAT ABOUT ALL THOSE BIG FIRES IN TALL BUILDINGS THAT DON’T CAUSE COLLAPSE, AND THE LITTLE FIRES IN BUILDING 7? Richard Gage and other 9/11 controlled demolition conspiracists like to show an NYPD photograph of small fires on the north face of Building 7. That’s not the side where tons of flaming debris from the towers smashed into the south face, creating huge gashes and fires on multiple floors. In our debate Gage claimed that the videos I played showed smoke but no fire. When the fires first started on the southwest corner of Building 7, the dust was blocking the view. NIST reported that many fires burned themselves out in 20-40 minutes and then moved on. The fires left behind not only burned out areas, but structurally weakened areas as the beams and columns expanded, sagged, and contracted again. Then the fires started moving to the interior of the building. Is he suggesting that all that smoke wasn’t evidence of fire, or that burned out areas went back to full structural strength?

No plane hit WTC Building 7. Instead, it was engulfed in hundreds of feet of flaming debris smashing into it.

9 WHAT ABOUT JANE STANDLEY, THAT BBC REPORTER WHO ANNOUNCED THAT BUILDING 7 HAD ALREADY FALLEN WHEN IT WAS STILL STANDING RIGHT BEHIND HER? This one is irritating to a guy like me who’s been in radio for over 30 years. Reporters make mistakes! What possible value could there be in letting the BBC in on the “conspiracy”? Here’s what probably happened: Deputy Chief Peter Hayden of the New York Fire Department recalled: “We had our special operations people set up surveying instruments to monitor, and see if there was any movement of [WTC 7]. We were concerned of the possibility of collapse of the building… One particular engineer there, we asked him, if we allowed it to burn could we anticipate a collapse, and if so, how soon?… And it turned out that he was pretty much right on the money, that he said, ‘In its current state, you have about five hours.’” Other errors in reporting show the chaos of the day, not a well-oiled conspiratorial machine at work. To wit:

CNN Reported at 11:07 am that Building 7 had collapsed at 10:45, or 15 minutes after the second tower collapse at around 10:30. CNN got their misinformation from the respected news agency Reuters, which picked up an incorrect report. They have issued this statement: “On 11 September 2001 Reuters incorrectly reported that one of the buildings at the New York World Trade Center, 7WTC, had collapsed before it actually did. The report was picked up from a local news story and was withdrawn as soon as it emerged that the building had not fallen.”

On 9/11, reporters also said that Camp David had been hit by a plane. Forbes magazine reported that “A car bomb exploded outside the State Department, according to State Department sources.” CBS News reported that as many as eight planes have been hijacked and only four have been accounted for.

It is not hard to imagine how such mistakes could be made, especially when there is no time to sift through and analyze fast-moving information. As NIST reported, “The large dust clouds generated by the collapse of WTC 1 hid the lower portions of WTC 7 from view for over 20 min following the collapse.” So firefighters on the ground saw only dust where Building 7 was until around 10:50 am and may have thought it had come down.

10 WHAT CAUSED BUILDING 7 TO COLLAPSE? Many firefighters reported seeing structural deformations of Building 7 hours before its collapse, including the top FDNY fire Chief Daniel Nigro, who stated, “I feared a collapse of Building 7 (as did many on my staff). The collapse of WTC 1 damaged portions of the lower floors of 7. Building 7 was built on a small number of large columns providing an open Atrium on the lower levels. Fires on many floors of WTC 7 burned without sufficient water supply to attack them. For these reasons I made the decision (without consulting the owner, the mayor or anyone else—as ranking fire officer, that decision was my responsibility) to clear a collapse zone surrounding the building and to stop all activity within that zone. Approximately three hours after … WTC 7 collapsed. Conspiracy theories abound and I believe firmly that all of them are without merit.”

In a World Trade Centre Task Force Interview, FDNY Lieutenant Rudolph Weindler said: “So we left 7 World Trade Center… and Captain Varriale told Chief Coloe and myself that 7 World Trade Center was badly damaged on the south side and definitely in danger of collapse. Chief Coloe said we were going to evacuate the collapse zone around 7 World Trade Center, which we did.”

And Deputy Chief Peter Hayden said: “We saw a bulge in the southwest corner between floors 10 and 13, and we had put a transit on that, and we were pretty sure she was going to collapse.”

Another Building 7 eyewitness was Michael Hess, Mayor Giuliani’s chief lawyer. He and fellow city worker Barry Jennings got caught in Building 7 and barely escaped with their lives. Michael Hess said that he heard and felt the building shake like an earthquake for 5–10 seconds prior to the collapse of either tower. But in 2007, he too changed his story, claiming in a BBC interview that he got his timing wrong and that the 10-second-long earthquake sound was most likely caused by tower debris hitting the building later in the morning. “There were no explosions. That was caused by the north half of #1 falling onto the southern half of our building.” He compared what he heard to a loud rumbling earthquake, not the staccato blasts of explosions.

11 WHAT ABOUT THOSE ACCOUNTS OF EXPLOSIONS IN THE TWIN TOWERS? I read 50 randomly selected accounts out of some 118 or so accounts from firefighters of explosions from the New York Times. None were of explosions before the actual collapse. Those accounts Gage found concentrated around the core and the basement where explosions from the jet fuel traveling down the elevator shafts caused several explosions and fireballs. Out of 5000 former and current FDNY 9/11 employees, only ten have come out and said they believe bombs were placed in these buildings. Further, firefighters have personally told me that explosions in office fires are not uncommon. Here is a list of a few things that explode in an office fire:

• HVAC equipment including condensers and compressors
• Cleaning supplies
• CRT type TV’s and computer monitors.
• Large motors that have an oil reservoir for lube. (Elevator lift motors)
• Hydraulic pistons found in office chairs.
• Tires in vehicles
• Steam explosions when water hits a hot fire or molten aluminum
• Propane tanks

If bombs were going off to create a precise controlled demolition, then there would be a pattern. Eyewitness accounts of explosions were random: fireballs, mere flashes of light, ground shaking with no other apparent effect. This is consistent with the kinds of random effects of fires spreading through buildings and down the elevator shaft. Eyewitness Philip Morell talked of explosive sounds like bombs in a 9/11 Mysteries video clip, but I went back to the complete original interview. The director cut out the part where he then explained that he ran over to the noise and discovered that the explosive sounds were actually from a crashing freight elevator, which did indeed create a tremendous crashing thud felt throughout the basement.

12 WHAT ABOUT THE FREE-FALL COLLAPSE OF BUILDING 7? That is the silver bullet that proves controlled demolition! NIST studied the collapse of one face of the 47-story Building 7 and found that indeed, on that one face, it collapsed “at gravitational acceleration” for eight stories over 2.25 seconds. The rest of that collapse was at considerably less than free-fall. After the internal supports collapsed, the perimeter walls were pulled inward. Every time a column snapped like a stick, it shifted its load at the speed of sound to other columns, and the collapse “gradually” accelerated over about two seconds. In phase two, the building was indeed collapsing at free-fall acceleration.

Free-fall collapse speed does not mean no resistance, it means no net resistance. Those collapsing beams still clinging to the walls functioned as levers. So there were three forces at work on Building 7 during its collapse, and the sum of these three forces varied with time: the constant downward force of gravity, the variable upward force of residual structural resistance, and variable leveraged downward forces due to connections to other parts of the building. The leveraging forces may have briefly accelerated parts of Building 7 at greater than 1G, and in fact the NIST Report shows very slightly faster than free-fall for a second or so, though that could just be the margin of error.

“What about” vs. “If… then”

The 9/11 controlled demolition theorists seem to like the “what about…” challenge. They know that even the most intelligent layperson can’t answer all their questions, and even if you can answer five “what about” questions in a row, then they’ll give you a real zinger, like this one from Richard Gage: “What about the EPA’s Erik Swartz who said they found 1,3-diphenylpropane at levels ‘that dwarfed all others. We’ve never observed it in any sampling we’ve ever done.” Unless you’ve checked, you won’t know that Gage edited out the next sentence of the Times Union article where that first appeared, which continues, “He also said it was most likely produced by the plastic of tens of thousands of burning computers.” Gage thinks 1,3-diphenylpropane was used for the sol-gel solution for safe storage of nanothermites. The patent lists pharmacological uses such as treating complications associated with metabolic syndrome, insulin resistance, diabetes, dyslipidemias, atherosclerosis, cardiovascular diseases, obesity, hypertension, inflammatory diseases, neurodegenerative pathologies, Alzheimers, or cancers but never mentions thermites or even plastic computer parts.

Instead of the “What about” game these conspiracy theorists play, I prefer the “if … then” approach:

If 4500 degree thermitics had been used to pulverize almost every inch of every concrete floor, then firefighters could not have walked on top of the debris pile that was left behind after the collapse. This photo shows that large parts of the buildings were left intact and not pulverized.

• If 4500 degree nanothermites were used to pulverize almost every inch of every concrete floor, then how could there have been millions of sheets of paper with an ignition temperature of only 451° raining down on the sidewalks?
• If 4500 degree nanothermites were used extensively even at the top to cause a supposed upward explosion, then why were first responders able to walk over the wreckage less than an hour after the Tower collapses?
• If there were 2800 degree rivers of molten steel in the debris, then why do NASA thermal images show maximum temperatures in the rubble of only 1400°?
• If the debris pile had 2800 degree temperatures, then why were firefighters able to pour millions of gallons of water all over it and not trigger the deadly thermal explosions that are caused when water comes in contact with molten steel or iron?
• If nanothermites pulverized everything, then why did the debris pile include a 13-story high facade?
• If classic controlled demolitions create minimal damage to adjacent structures, then why did the Verizon Building suffer $1.4 billion in damages?
• If the lateral ejection of beams were caused by explosive nanothermites, then there would have been deafening 140 db sounds that can’t be muffled by more than a few db or you lose the explosive force of the shock wave itself.
• If the South Tower tilted 22° at first, then controlled demolition experts could not have righted it mid-collapse.
• If nanothermites were used, then they would have spontaneously detonated at well under 1000° F. and would not have been controllable; no signal receiving device could have survived the fires and continued to receive the destruct command.
• If there had been large explosions prior to the collapse, then they would have been a part of the seismic record, and they were not.

You get the idea. My YouTube videos offer 235 reasons for natural collapse just like these, along with abundant videos and photos. Investigate a little deeper and you’ll find that the science just doesn’t support the views of the Architects and Engineers for 9/11 Truth. The truth is out there and we know what it is.

About the Author

Chris Mohr is a lifelong science hobbyist, the former publisher and editor of the classical radio publication On The Air Magazine, and composer of the opera From The Realm of the Shadow on Naxos Records. He has hiked up 1000 mountains, bicycles 2000 miles per year, enjoys scuba diving and is a classical music and opera fanatic. He has hosted a prison meditation program for 16 years.

References

1. Shermer, M. 2005. “Fahrenheit 2777: 9/11 has generated the mother of all conspiracy theories.” ScientificAmerican.com.
2. Meacham, Brian. Fire and Collapse, Faculty of Architecture Building, Delft University of Technology: Data Collection and Preliminary Analyses.
3. Eagar, Thomas W. and Christopher Musso. 2001. “Why Did the World Trade Center Collapse? Science, Engineering, and Speculation” JOM, 53 (12) (2001), pp. 8–11.
4. NIST NCSTAR1 Federal Building and Fire Safety Investigation of the World Trade Center Disaster. 2005. Final Report on the Collapse of the World Trade Center Towers
5. Zdeněk P. Bažant, Jia-Liang Le, Frank R. Greening and David B. 2008. “What Did and Did not Cause Collapse of WTC Twin Towers in New York.” Journal of Engineering Mechanics ASCE, Vol. 134
6. RJ LeeGroup Inc. 2003. Damage Assessment 130 Liberty Street Property Report. WTC Dust Signature Report: Composition and Morphology Summary Report.
7. World Trade Center Disaster Study. 2002. National Institute of Standards and Technology (NIST). www.nist.gov