On January 19, 2017, the Plasco building, a 17-storey steel high-rise in Tehran, caught fire. The blaze began on one of the building's upper floors and then spread quickly through the tower's sprinkler-less garment workshops. As the Tehran fire department battled the nearly unreachable fire, the steel skyscraper collapsed in full view of Iranian state television cameras.
Firefighters at the scene after the collapse of the Plasco building in Tehran. Photo: AP
Sixteen firefighters and at least six civilians were found dead in the smouldering debris. Tens of thousands of citizens publicly mourned the firefighters when they were laid to rest in the "martyrs" section of the Behesht-e Zahra cemetery in Tehran. In addition to the human toll, Tehran also lost a landmark building, the first steel framed high-rise to be erected in the city in the 1960s.
Since the Plasco building collapse occurred one day before the Trump inauguration, most Americans were too busy preparing for our own national calamity to pay attention to the disaster in Iran. However, one group of ideologically invested Americans responded immediately: Architects and Engineers for 9/11 Truth (AE911Truth), a organisation which promotes the conspiracy theory about a "controlled demolition" that brought down the World Trade Center skyscrapers and a subsequent "cover-up."
AE911Truth, probably most starched and ironed of all the 9/11 conspiracy groups, was formed in 2006 as a place for building experts to advocate for a re-investigation of the World Trade Center attacks. AE911Truth has spent the past decade convincing a brain trust of YouTube commenters that tall buildings simply cannot collapse due to fire. But rather than accepting the Plasco Building as a thundering rebuttal to their theories, AE911Truth concluded that Plasco was also a controlled demolition.
Before the dust had even settled in Tehran, AE911Truth issued a press release urging President Hassan Rouhani to investigate the "possible use of explosives" in the destruction of the tower.
The organisation, which is now a 501(c)(3) non-profit, stands out from the throng of 9/11 conspiracy organisations due to its roster of members who have letters after their names and who possess at least a passing knowledge of engineering lingo. The founder, president, and one of the few full-time employees is Richard Gage, a wide-tied former architect who demonstrates his understanding of structural mechanics using cardboard boxes.
(My attempts to contact Richard Gage or representatives of AE911Truth were either ignored or rejected, but they did wish us "best of luck with your faux journalism hit piece.")
AE911Truth also differentiates itself by rejecting the kookiest 9/11 theories: That no planes were used in the attacks, that there were nuclear devices hidden in the WTC basement, and that the towers themselves were completely empty stage props or holograms. (Israel figures heavily in all of these scenarios.)
Instead it argues that unnamed nefarious entities demolished the towers with well-hidden pre-planted explosives. To explain away the absence of audio or visual evidence of typical demolition charges, AE911Truth argues that the buildings were brought down by nano-thermite, a material with a highly exothermic reaction which hardly exists outside of advanced physics journals.
Nano-thermite, the phlogiston of the conspiracy narrative, would have silently severed critical structural members and triggered a progressive collapse. In his role as head of AE911Truth, Richard Gage travels to conferences around the world (both alternative and mainstream) and lectures audiences on the finer points of the controlled demolition theory.
AE911Truth has conspicuously focused on the collapse of World Trade Center Tower 7, a 47-story building which caught fire after the destruction of WTC1 and then collapsed about seven hours later. This building has long been the truther's ace in the hole because its collapse -- which claimed zero lives -- was hardy notable among the other atrocities of the day.
Since the average joe has little or no knowledge about the existence of WTC7 and no preconceived notions about its demise, the conspiracy theorist can lay out their controlled demolition story nearly unrebutted.
In addition, no plane ever hit the building, so the cause of its catastrophic structural damage is not immediately apparent, especially when compared to WTC1 and WTC2. (The consensus opinion on WTC7 is that uncontrolled fires eventually weakened steel members where the structure spanned over a pre-existing electrical substation. This led to a series of internal failures within the eastern side of the building which progressed into a global structural collapse.)
The conspiracy theory presented by Gage and AE911Truth is based on three core axioms: 1) Steel skyscrapers cannot collapse due to fire, 2) buildings that collapse should tumble down slowly (rather than at what they call "free-fall speed"), and 3) a collapsing building should topple over eccentrically rather than falling straight down. These arguments may not make any sense when examined closely, but they are persuasive bumper sticker statements, and rebutting the claims requires a level of engineering knowledge that the average person may lack.
Iranian firefighters remove debris of the Plasco building which was engulfed by a fire and collapsed, in central Tehran, Iran. Photo: AP.
Prior to Plasco, it was difficult to produce counterexamples that would immediately disprove these truther axioms because out-of-control high-rise fires just don't happen very often. Small fires occur as frequently in skyscrapers as they do in any other type of building, but they rarely flash over into all-consuming infernos. There are obvious risks in stacking human beings up in columns hundreds of metres in the air, so architects and engineers make special considerations for protecting tall buildings from from fire.
Passive protection systems, such as firestops at floor penetrations and fire-rated doors at stairwells, are designed to compartmentalise blazes and prevent them from spreading. Active protection systems like sprinklers go one step further and suppress fire once heat and smoke are detected. Disasters like the Grenfell Tower Fire in London demonstrate the appalling consequences of neglecting these key safety considerations.
When major skyscraper blazes have occurred, 9/11 truthers have cited the charred but standing structural skeletons as proof of their narrative. Fires scorched Beijing's 34-story Television Cultural Center in 2009 as well as Dubai's 67-story Torch in 2012 and 63-storey Address in 2015, but none of these buildings collapsed. Conspiracy theorists loudly declared these incidents to be proof that fire alone cannot take down a skyscraper.
However, the critical characteristic that AE911Truth ignores is that both towers in Dubai were concrete buildings, and Beijing's TVCC Building was a composite structure. The aforementioned Grenfell Tower was also a concrete structure.
Pawel Woelke, PhD, P.E., an engineer and expert in structural failure, notes, "Concrete is a material that doesn't really soften nearly as easily due to high temperature, mostly because it's porous. It's a much more porous material, the void/volume fraction is massive compared to steel." Concrete is somewhere between 20 and 40 times less thermally conductive than steel and concrete structural systems also tend to be more massive than steel structures, meaning that much more energy is needed to heat them to the same degree.
Concrete and steel are both materials used in the superstructures of skyscrapers, but they behave very differently under prolonged exposure to fire. This knowledge seems to be lost on AE911Truth, which has trumpeted every concrete high-rise blaze as definitive proof that fire simply cannot cause a steel building to collapse.
But fire's deleterious effect on steel is a well-known phenomenon and has been studied by engineers since at least the 1870s. Woelke comments, "At 450 degrees [Celsius] or so, you get basically a 50 per cent drop in strength and stiffness, and that's very significant." Prolonged exposure to heat from well-ventilated home or office fires (which can reach 1100°C) can decrease steel's yield strength and modulus of elasticity more than enough to cause the structure to fail. Heat also causes steel to expand, which means that beams, girders, and braces push outward on already weakened structural connections.
Old school builders used terra cotta or brick to insulate structural steel members from heat, but engineers today opt for concrete, cementitious spray-on coatings, or intumescent paint. But the goal of fireproofing is not to ensure that the building will survive an hours-long inferno. Instead, as Woelke says, "The primary objective is to allow evacuation of the building, to increase the amount of time that the occupants have to exit the building.
There is no assumption that a building that is allowed to burn for hours and hours is going to be totally fine." A well-designed building is one that grants occupants enough time to evacuate before the steel is weakened to the point of failure.
The Plasco Building stood for hours after catching fire, allowing scores of merchants to evacuate to safety. When the flames finally overwhelmed the steel structure, it fell quickly and vertically, in direct contradiction to the core beliefs of Architects and Engineers for 911 Truth. In spite of the similarities between the demise of the Plasco Building and WTC7, AE911Truth had gone full "When Prophecy Fails" by committing itself even further to its conspiracy narrative.
One month after the fire, AE911Truth released a paper confirming its own unsolicited suggestion that the Plasco building was demolished with pre-planted explosives. Most of the links in footnotes of the paper point to YouTube videos and th organisation's own PDF documents. As proof of its claims, it cites puffs of smoke emanating from the collapsing building (demolition squibs), large clouds of dust and ash (proof of highly energetic explosive material) and the presence of supposedly molten material in the debris pile (nano-thermite's persistent exothermic reaction).
Since truthers made these exact same observations about WTC7, and since WTC7 must have been a controlled demolition, then clearly the Plasco Building was demolished as well. In a perfect infinite loop of anti-logic -- like a snake slithering into its own arsehole -- an exact refutation of AE911Truth's beliefs has instead vindicated them completely.
The debates over Plasco's collapse have raged in the same hundred page forum threads and YouTube comment sections as the 9/11 arguments of yesteryear. Tony Szamboti, a mechanical engineer, JFK assassination conspiracy theorist, and longtime AE911Truth foot soldier, has been the most prominent truther in the trenches, battling giddy debunkers on the International Sceptics Forum (a science-centered discussion board that grew out of the James Randi Educational Forum, which often focuses on debunking hoaxes, conspiracies and popular myths) and attempting to salvage the time he invested in a battered ideology.
On February 23, Szamboti appeared on a podcast called "9/11 Free Fall," and pushed back against the Plasco narrative, saying "There was a number of people who were trying to say 'Look, a building can collapse by fire!' Well, not so fast. Certainly looks like there were explosions in the building." Szamboti may have convinced himself that Plasco collapsed due to explosions, but he seems to have failed to win over the crowd at International Sceptics Forum; Szamboti, who had posted there almost 5000 times since 2008, fled the forums two weeks before his podcast appearance. He did not respond to request for comment on this article.
While the broader AE911Truth organisation is engaging in a losing battle online, CEO Richard Gage has blithely continued to deliver his conspiracy presentations. In June 2017, he spoke at The Red Pill Expo in Bozeman, Montana, alongside goldbugs, doctors who cure cancer with aromatherapy, and fake British "Lord" Christopher Monckton.
Ironically, it is AE911Truth's own nominal interest in science that necessitates an intense defence of such an untenable position. The conspiracy theorists who blame 9/11 on Israeli directed energy weapons and reptilian seismic shape charges haven't bothered to react to the Plasco disaster because they don't have to. Their detachment from reality is so sharp that no real world evidence could ever inform their beliefs.
David Dees hasn't even mentioned the Plasco building. However, for groups like AE911Truth to continue to present themselves as rational, educated experts, they must at least appear to address conflicting evidence whenever and wherever it arises.
In April 2017, the investigation led by the government of Iran ignored AE911Truth's recommendations and declared fire to be the sole cause of Plasco's collapse. A further parliamentary inquiry pinned the blame of the fire on unauthorised heating devices on the 10th floor and decried the substandard ventilation, lighting and fire protection within the doomed building.
As the world moves on and a new 10 story structure starts construction at the site of the Plasco collapse, the sentinels of AE911Truth continue their commitment to the conspiracy, scanning the horizon, waiting for the next controlled demolition cover-up.
Alex Weinberg, P.E. is a structural engineer and writer living in New York City.