Despite strong contrary arguments, a McMaster University engineering professor steadfastly maintains the collapse of three World Trade Center buildings after the infamous 9/11 attacks can only be adequately explained if “controlled demolition” is part of the equation.

Robert Korol, a civil engineering professor emeritus and a fellow of the Canadian Society of Civil Engineering, authored a report with Steven Jones, former professor of physics at Brigham Young University, Anthony Szamboti, a mechanical design engineer in the aerospace and communications industries and Ted Walter, director of strategy and development for Architects & Engineers for 9/11 Truth (AE911Truth). The report was titled 15 Years Later: On the Physics of High-Rise Building Collapses published last year in the Europhysics News journal which is a magazine for the European physics community and owned by the European Physical Society.

In the controversial paper, the authors reflect the overarching premise of the AE911Truth, which has collected 2,936 signatures from engineers and architects. Among those petition signatories are 19 who earned their respective degrees in Canada, including 15 who live here.

AE911 Truth posits: “there is sufficient doubt about the official story and therefore the 9/11 investigation must be re-opened and must include a full inquiry into the possible use of explosives that might have been the actual cause of the destruction of the World Trade Center Twin Towers and Building 7.”

The group has long been controversial and its arguments have ignited many debates. The overwhelming consensus has favoured the official explanation which states that fires burning inside the buildings weakened the structural steel and triggered their collapse. This has consistently been reaffirmed by U.S. National Institute of Standards and Technology (NIST) over the last 16 years.

The Europhysics News editors also recognize the controversy, publishing the article with the following note: “This feature is somewhat different from our usual purely scientific articles, in that it contains some speculation. However, given the timing and the importance of the issue, we consider that this feature is sufficiently technical and interesting to merit publication for our readers. Obviously, the content of this article is the responsibility of the authors.”

Reached at his home in Dundas, Ont., Korol shrugs off the controversy.

“I’ve been scratching my head over this one since it happened on Sept. 11, 2001,” he says. “I just couldn’t understand how those buildings collapsed. It didn’t make sense.”

While the most iconic images of that fateful day are the collapse of the twin towers World Trade Center 1 (WTC 1) and World Trade Center 2 (WTC 2) within moments of each other, following the fires started by a passenger airplane crashing into each of them, there is a third building most often cited as the smoking gun in the “controlled demolition” theory. This building, World Trade Center Building 7 (WTC 7) was not hit by any aircraft and yet it too imploded like a house of cards, says Korol and his co-authors and others note it housed CIA and Secret Service offices.

“Indeed, neither before nor since 9/11 have fires caused the total collapse of a steel-framed high-rise — nor has any other natural event, with the exception of the 1985 Mexico City earthquake, which toppled a 21-storey office building,” they argue. “Otherwise, the only phenomenon capable of collapsing such buildings completely has been by way of a procedure known as controlled demolition, whereby explosives or other devices are used to bring down a structure intentionally.”

Korol, who has taken contrarian positions on other engineering-related issues, says it’s important to keep challenging the status quo because we need to know how and why the buildings collapsed in order to prevent reoccurrences.

“The fires were on the upper floors, there’s little chance the heat would have spread down and caused the steel columns, or the connectors or floor beams, to sufficiently weaken and collapse in the twin towers,” he tells the Daily Commercial News.

“Also they were treated with a fire retardant which would have insulated them.”

Further, he says, when the structures did fail they did so with such explosive force that pulverized concrete was ejected at high velocity and scattered on a debris field some 370 metres away.

The most probable explanation is a controlled explosion and mostly likely using thermite, he says, adding in the case of WTC 7 some 67 per cent of the supporting steel strength in Column 79 — pinpointed as the cause of the fatal collapse — would have to be lost before it failed and that would mean temperatures of 660C.

The paper also notes sprinkler systems would have reduced heat factors, while the overall design of the steel structure would isolate any failure and prevent a domino-effect collapse.

The NIST however maintains the heat factor triggered an expansion in floor beams, pushing them off their seats and causing the collapse when other components also failed due to thermal expansion.

Korol and other likeminded colleagues, stubbornly disagree.

“The evidence points overwhelmingly to the conclusion that all three buildings were destroyed by controlled demolition,” they conclude “Given the far-reaching implications, it is morally imperative that this hypothesis be the subject of a truly scientific and impartial investigation by responsible authorities.”

The NIST’s 2008 report on WTC 7, however, takes direct aim at the AE911Truth theories: “Our take-home message is the collapse of World Trade Center 7 is no longer a mystery,” NIST lead investigator Shyam Sunder told a press conference. “WTC 7 collapsed because of fires fueled by office furnishings. It did not collapse from explosives or from diesel fuel fires.”

He said WTC 7 marks the first recorded event of a 15-storey structure or more collapsing due to fire.

“What we found was that uncontrolled building fires — similar to fires experienced in other tall buildings — caused an extraordinary event, the collapse of WTC 7,” he said.

The NIST report says debris from WTC 1 sparked fires on at least 10 floors of WTC 7 at its southern and western faces. However, the fires on floors seven through nine and 11 through 13 burned out of control because the sprinklers failed when watermain supply lines were damaged when WTC 1 and 2 collapsed.

Seven hours later,“a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building,” the NIST concluded.

“The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories,” stated the NIST.

In a shot at AE911, the NIST report noted they did look at the possibility of a controlled demolition: “Hypothetical blast events did not play a role in the collapse of WTC 7.”

The NIST said “no blast sounds were heard on the audio tracks of video recordings during the collapse of WTC 7 or reported by witnesses.”

Further, they argued, even a small blast with enough energy to dislocate Column 79 would have emitted a sound level of 130 decibels (dB) to 140 dB at a distance of at least half a mile, if unobstructed by surrounding buildings.

“This sound level is consistent with a gunshot blast, standing next to a jet plane engine, and more than 10 times louder than being in front of the speakers at a rock concert,” they said noting all the recordings of the events that day do no show any spikes from explosions.

“For the building to have been prepared for intentional demolition, walls and/or column enclosures and fireproofing would have to be removed and replaced without being detected. Preparing a column includes steps such as cutting sections with torches, which produces noxious and odorous fumes.”

The investigation also looked at thermite (a combination of aluminum powder and metal oxide) as an explosive source. The NIST calculated that 100 lbs. of thermite would have been needed to damage a steel column that weighs approximately 1,000 lbs. The thermite would need to be “placed around the column, ignited, and remain in contact with the vertical steel surface as the thermite reaction took place. This is for one column, presumably, more than one column would have been prepared with thermite, if this approach were to be used,” explained the NIST.

Further, the NIST argued, it is unlikely that 100 lbs. or more of thermite could have been brought into WTC 7 and placed around the columns prior to Sept. 11 without being detected.

Editor’s Note: The beliefs of AE911Truth are solely those of its supporters and in no way reflect those of ConstructConnect’s Daily Commercial News or the company.