Paris Must Learn From Citicorp Tower’s Fatal Flaw | SAFETY DOC PODCAST #98 [Podcast]

[Podcast] In 1978, an engineering student discovered a fatal structural flaw in New York City’s just-completed Citicorp Tower. What happened next wasn’t made public for nearly 20 years!

DIRECT LINK to MP3 of this Episode:


Dr. Perrodin juxtaposes the Citicorp Tower dilemma with the modern day unfolding crisis of massive lead contamination resultant of the April, 2019, Notre Dame Cathedral Fire. Per the Guardian (in an article by Angelique Chrisafis dated May 9th), “The Paris police statement on Thursday said that on the surface of pavements and gardens immediately adjoining the cathedral, lead levels were found to be very high: between 32 and 65 times the recommended limit by French health authorities. The areas closest to the cathedral are currently closed. Lead levels are also high within the cathedral itself.”

Wow! Dr. Perrodin notes that similar “defiant” articles are surfacing that both bring awareness to the lead contamination and bluntly state the dire short and long term health risks associated with approximately 500,000 pounds of lead vaporized from the cathedral’s roof. Chrisafis’s article later notes, “But the French environmental campaign group Robin des Bois has warned that about 300 tonnes of lead from the cathedral’s roof and steeple had melted in the blaze. The cathedral has been reduced to the state of toxic waste,” the association said shortly after the fire, urging authorities to detoxify the tonnes of rubble, ash and wastewater produced in the disaster.


David states that Paris officials are aware of the breadth and depth of the lead contamination issue and that there’s likely a contingency plan being assembled to deal with thousands of people impacted by lead in their bodies secondary to the Notre Dame fallout. Dr. Perrodin wasn’t surprised that areas close to the cathedral weren’t registering high levels of lead contamination as he points out that the thick plume of lead-laden smoke probably carried the highest concentrations of lead 2-3 miles from the cathedral before cooling and the particles dusted over Paris.


Yep, admission of widespread lead contamination would destroy tourism (the economic engine of Paris) and how do you tackle lead abatement in a population dense region? Chernobyl could be isolated – you can’t do the same with Paris. Also, imagine the litigation! What happens to the $billion in donations to rebuild NDC when thousands of people rack up medical bills due to complications from lead exposure? The public health crisis would be off the charts!


Chief structural engineer, William LeMessurier, is largely credited as the person responsible for creating the wondrous Citicorp Tower in 1977. He was a thoughtful engineer and put the design of the tower through its paces with wind test scale simulations in the world’s best lab and worked the standard battery of industry calculations. The tower was built in an innovative way to accommodate an existing church. Hence, the pillars that supported the tower were moved from the corners to the middle of each wall. A strong central pillar, like a mushroom stem, also supported the structure.


LeMessurier received a call from an engineering graduate student who was puzzled at how the structure could withstand perpendicular winds. LeMessurier listened and upon further study of the building and learning of some last-minute changes that included having tension braces bolted in place rather than welded in place, he was terrified to be informed that the tower would collapse with encountering a 70 MPH wind from a certain angle. The tower had a tuned dampening system that would offset such winds, but it was electrical – and if the power went out during a storm – well, lights out!


LeMessurier the Citicorp brass, insurance folks, NYC officials and the NYC welder’s union acted in unison to quickly fortify the tower. They also hired 3 weather agencies to rigorously track weather conditions and formulated a 10-block evacuation plan in case of high winds.


The workers in the tower or in proximal structures were NOT made aware that the tower could collapse. The decision to withhold this information was done to prevent panic and massive economic disruption to the city. In addition, officials believed they could evacuate the zone in time. However, Lemessurier is most strongly criticized for not sharing the wind shear information with the greater engineering community for several years. How many buildings were constructed AFTER Citicorp Tower without calculating for the peculiar wind shear factors confirmed by Lemessurier? In a recorded 1997 presentation he gave at a university, Lemessurier implies that other tall buildings existed that were susceptible to failure due to similar wind dynamics. How many of those structures might have been built differently, or retrofitted, had Lemessurier’s knowledge immediately been shared with building engineers?


Dr. Perrodin presents different scenarios that happen in schools. Each impacts the safety of the setting. How do the schools respond to each scenario if following what is unfolding in Paris or per the protocol established by the team that quietly mitigated the Citicorp flaw?


Looking for Dr. Timothy Ludwig, PhD?

Dr. Perrodin’s “Safety Doc Podcast” negotiates school and community safety. To be informed about industrial safety, please contact Appalachian State University Professor Dr. Timothy Ludwig, PhD, at


Learn About the Nation’s Leading Bullying & School Safety Reporting System – SPRIGEO

Purchase Dr. Perrodin’s Book: Schools of Errors – Rethinking School Safety in America