The new WTC 7 building (right) in New York

The new WTC 7 building (right) in New York

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What changes have been made as a result of the World Trade Center (WTC) investigation conducted by the National Institute of Standards and Technology (NIST)?  Are tall buildings around the world safe from the risk of global collapse due to fire as described by the official explanations?

In 2008, NIST began claiming that its investigation would help ensure the safety of future buildings.  NIST said that such buildings “should be increasingly resistant to fire, more easily evacuated in emergencies, and safer overall” as a result of the WTC investigation.  Commerce Secretary Carlos Gutierrez, the Bush Administration cabinet member in charge of NIST at the time, said, “The lessons learned from the tragic events of 9/11 have yielded stronger building and fire codes for a new generation of safer, more robust buildings across the nation.”[1]

Is this true?  If so, we should be able to see improvements being made to the design and construction processes for tall buildings around the world.  We should also expect that existing buildings would be evaluated for design problems and retrofitted in an urgent manner to ensure that fires do not bring buildings crashing down as they did on 9/11, killing thousands of unsuspecting victims.

Unfortunately, there are no signs that such design evaluations and retrofit projects have occurred. This is a strong indication that the international building community has not taken the NIST WTC reports seriously.

In a few stunning instances, the NIST findings were never considered at all prior to building design and construction.  An example is the new WTC building 7, which was fully completed in 2006. That same year, NIST spokesman Shyam Sunder was saying, “We’ve had trouble getting a handle on building No. 7.”[2] To clarify, in 2006 NIST had no idea what happened to the original WTC 7, a 47-story skyscraper that was not hit by a plane yet collapsed into its own footprint in a matter of seconds on 9/11. Therefore the new, even taller, WTC 7 could not have incorporated any design or construction changes resulting from the NIST investigation. Apparently people still use the building, however, and do not seem bothered by the risk.

How about for other buildings in New York City and elsewhere, including the widely publicized replacement for WTC 1 being completed this year?  In order to answer that question, we should review a little history behind the NIST WTC investigation.

The NIST WTC Investigation

According to NIST, the original Twin Towers were built to meet the 1968 NYC building code requirements.[3]  This code required three hours of fire resistance for the steel column components and two hours of fire resistance for the floor assemblies.  A startling discrepancy here is that the south tower was said to be completely destroyed less than one hour after the fires began.  And what people often don’t realize is that fire is the primary explanation for failure of all three WTC buildings.

NIST did not explain this discrepancy directly.  Instead, the NIST WTC reports, which amount to tens of thousands of pages, reflected the results of computer modeling that proposed three root causes.

  • “Widely dislodged” fireproofing – the Twin Towers
  • Linear thermal expansion – WTC 7
  • “Progressive global collapse” – all three buildings [4]

Progressive global collapse was a term that NIST used frequently throughout its investigation despite the fact that no tall building had ever collapsed completely due to fire.  In fact, the only three instances of progressive global collapse for any reason other than demolition occurred all in the same place (at the WTC) at the same time (on 9/11).

With respect to the fireproofing (i.e. insulation) loss in the towers, NIST said, “The WTC towers would likely not have collapsed under the combined effects of aircraft impact and the extensive, multi-floor fires if the thermal insulation had not been widely dislodged or had been only minimally dislodged by aircraft impact.”

At the time of the 9/11 attacks, the WTC towers were undergoing a fireproofing upgrade to better ensure the buildings’ fire resistance.  In an incredible coincidence, the floors where the full fireproofing upgrades had been completed were the same floors that were struck by the aircraft on 9/11.[5]

The true condition of the fireproofing in the WTC towers at the time of impact has been misrepresented by supporters of the official account.  These official account supporters produce old photos of the fireproofing condition prior to the upgrades.  What they don’t tell you is that the upgraded fireproofing, for example on the impact floors of the north tower, was measured before the attacks and found to be 3.25 inches thick.  This was twice what was required by the NYC code.  What’s more, inspectors found that the adhesion, or bond strength, of the newly installed fireproofing was twice as high as what was required.[6]

How did this newly installed, superior fireproofing in the towers get “widely dislodged” as proposed by NIST?

We don’t know because NIST produced a startling lack of scientific evidence for its central claim that the fireproofing was widely dislodged.  In fact, the only evidence NIST presented for this was a test in which 15 rounds from a shotgun were aimed at various non-representative samples.  A shotgun may have been needed due to the fact that other tests NIST had performed showed the bond strength of the WTC fireproofing to be “considerably greater” than what was expected.[7]

For WTC 7, the root cause cited by NIST was the dislocation of a girder caused by the linear thermal expansion of floor beams.  The expanding composite beams were said to have caused the breakage of over one hundred high-strength bolts and other structural connections, and thereby the failure of a girder supporting a critical column.

However, other scientists submitted public comments to NIST about actual physical tests they had done, which NIST avoided entirely, that indicated such a sequence was not realistic.  “Having conducted numerous fire tests on composite beams, we have never observed this,” wrote Dr. David Proe of Victoria Universty.[8]

As a whole the NIST WTC reports were found to be unscientific and false.[9]  And because the computer models upon which these reports were ultimately based have never been made available to the public, the NIST findings cannot be replicated.

Ignoring NIST’s Recommendations

Regardless of the lack of scientific validity of the WTC reports, NIST represents a standard making body of the U.S. government and its findings should compel U.S. professionals to make changes to their practices. To see if building professionals and local government regulators have followed NIST’s lead, we should examine the relevant building codes for any updates resulting from the NIST WTC investigation.

The International Code Council (ICC)’s International Building Code (IBC) provides a general guidance for local code makers in the United States. Following the IBC code is not a requirement for local governments, however.  Translation of the code into local code requirements is strictly a discretionary decision.

Although the ICC praised NIST and its contractors for the hard work that had gone into the NIST WTC investigation, the fact is that ICC did not incorporate relevant changes into its IBC code as a result.

In its 2008 press release on the subject, NIST claimed that the IBC code had changed to “address areas such as increasing structural resistance to building collapse from fire and other incidents; requiring a third exit stairway for tall buildings; increasing the width of all stairways by 50 percent in new high-rises; [and] strengthening criteria for the bonding, proper installation and inspection of sprayed fire-resistive materials.”

Of course, additional and wider exit stairways cannot prevent the catastrophic collapse of a skyscraper from fire.  But NIST was not telling the truth about the ICC having adopted code changes to increase structural resistance to the kinds of building collapse phenomena proposed by the WTC reports.

A 2010 press release from NIST added “better communications” to the list of ICC-adopted recommendations from the WTC investigation.[10]  It’s true that the radios used by firefighters in the WTC were a concern, and were actually known by NYC officials to be faulty as early as 1993.[11]  However, no amount of radio-related code differences would have prevented the unprecedented destruction of the buildings.  Similarly, NIST’s evacuation recommendations had no relevance to the root cause of the WTC destruction.