Are Millions of
Business People At Risk of Dying In Collapsing Buildings?
February 13,
2014 by WashingtonsBlog safety-related public service announcements.
Death Traps? Millions of people work in or visit high-rise buildings É
assuming the buildings were more or less safe. But it turns out that there is a severe, lethal risk of
sudden collapse in even the best-made skyscrapers in America, Britain, Germany,
Japan and other nations worldwide.
A New Understanding Before 9/11, no modern steel-frame high-rise building
had ever collapsed due to fire.
9/11 radically changed our understanding of architecture and engineering
É Specifically, 3 steel-frame
buildings collapsed on that day. That includes one that was never hit by a plane, and had only small, isolated office fires prior to its
collapse. This was unexpected, as much hotter, longer-lasting fires have never
before brought down a modern steel-frame office building. For example,
the 2005 Madrid skyscraper fire Òreached 800 degrees Celsius (1,472 F), said Javier Sanz, head of Madrid firefighterÓ and lasted some 20 hours without collapsing. In other words, officials who write
building codes, architects and structural engineers had never before worried
about small office fires causing office buildings from collapsing. Appendix A of the Federal
Emergency Management AgencyÕs World Trade
Center Building Performance Study notes:
In the case of the fire at
One Meridian Plaza, the fire burned uncontrolled for the first 11 hours and
lasted 19 hours. Contents from nine floors were completely consumed in the
fire. In addition to these experiences in fire incidents, as a result of the Broadgate fire, British Steel and the Building Research
Establishment performed a series of six experiments at Cordington
in the mid-1990s to investigate the behavior of steel frame buildings. These
experiments were conducted in a simulated, eight-story building. Secondary
steel beams were not protected. Despite the temperature of the steel beam
reaching 800-900 ¡C (1,500-1,700 ¡F) in three tests (well above the
traditionally assumed critical temperature of 600 ¡C [1,100 ¡F]), no collapse
was observed in any of the six experiments.
Underwriters Laboratories
tested the steel components at the Twin Towers and found they could withstand
fires for hours without failure: ÒNIST [the government agency - National
Institute of Standards and Technology, a branch of the Department of Commerce -
responsible for investigating the collapse of the 3 buildings on 9/11]
contracted with Underwriters Laboratories, Inc. to conduct tests to obtain
information on the fire endurance of trusses like those in the WTC towersÉ. All
four test specimens sustained the maximum design load
for approximately 2 hours without collapsingÉ The Investigation Team was
cautious about using these results directly in the formulation of collapse
hypotheses. In addition to the scaling issues raised by the test results, the
fires in the towers on September 11, and the resulting exposure of the floor
systems, were substantially different from the conditions in the test furnaces.
Nonetheless, the [empirical test] results established that this type of
assembly was capable of sustaining a large gravity load, without collapsing,
for a substantial period of time relative to the duration of the fires in any
given location on September 11.Ó (NIST, 2005, p. 140).
Other fire tests have also
failed to cause failures at high temperatures. So the collapse of World Trade
Center Building 7 on 9/11 (not hit by a plane) was a surprise É and should be a
huge concern to the millions of people who work in office buildings
worldwide. To get to the bottom of
this issue, WashingtonÕs Blog reached out to a former manager at Underwriters
Laboratories – Kevin Ryan – to seek reassurance that the danger was
small for the millions of financial services industry workers, business men,
lawyers, web executives, and others who work in office buildings: [Question] WasnÕt
the steel used in the Twin Towers and Building 7 of inferior quality? So
as long as builders use better-quality steel, canÕt we be assured of safety?
[Kevin Ryan]
The steel used to build WTC Building 7 was the standard grade for high-rise
construction–still used to this day–called ASTM
A36 grade steel. It was not inferior in any way from the steel used
to make many of the other high-rise buildings in America. For the Twin Towers,
fourteen different grades of steel were used in the construction, including
A36, which has a nominal strength of 36 ksi. The
other grades used were higher strength steels like 100 ksi
WEL-TEN steel which was manufactured in Japan and
shipped to the States. The steel used in the Towers was actually far superior
to typical structural steel.
The official government reports on the destruction of the WTC buildings
did not find any problem with the quality of the materials or construction
methods used. And although those reports did make some recommendations for
changes to building codes, those changes have
not been
incorporated in municipal codes or
adopted by
the building
construction community.
[Question] You
write in Foreign Policy Journal: ÒAnd if people actually understood and
believed the official account of what happened at the WTC they would not enter
tall buildings because in doing so they would be putting their lives at risk.Ó
What do you mean? [Ryan]
What I mean is that high-rise buildings are designed and constructed to
withstand fires that are much worse than what we know existed in WTC Building
7. My former company, Underwriters Laboratories (UL), plays a big part in that
process. We know that UL did the fire resistance testing that was behind the
selection of the steel components for WTC7 because that fact is in the NIST
WTC7 report. Therefore the steel columns and floor assemblies should have
withstood 2 to 3 hours of intense fire in a testing furnace, as required by the
NYC code. But on 9/11, the fire lasted only 20 minutes in any given area,
a fact that NIST admits, and the entire structure was destroyed due to an
inexplicable failure to resist fire. Moreover, NIST abandoned its previous hypotheses that
suggested the destruction of WTC7 might have resulted from diesel fuel fires,
or damage from falling debris, or the design of the building. In the end, NIST
said that it was only the effects of the fire fed by office furnishings, on fully-fireproofed steel components, that caused the total
destruction of this 47-story building. And since no actions have been taken to
retrofit any existing high-rise buildings, we must assume that what happened to
WTC7, according to the official account, could happen to any tall building that
experiences a typical office fire.
No Change (?!) Given that 9/11 totally changed our
understanding of how dangerous small office fires could be, we couldnÕt believe
RyanÕs claim that Òchanges have not been incorporated in municipal codes or
adopted by the building construction community.Ó So WashingtonÕs Blog contacted Richard Gage, a practicing architect for more than two decades,
who has worked on most types of building construction, including one project
which used around 1,200 tons of steel framing: [Question] Have high-rise
architects and engineers changed how they build skyscrapers, to prevent
collapses after 9/11? And
have they changed how they build skyscrapers to prevent office fires from
knocking down steel buildings? [Richard Gage] No – they havenÕt made any
structural changes. No
structural changes?!
Either building code
writers, architects and engineers are cavalierly
ignoring this catastrophic new understanding of the extreme danger of small
office fires, or the investigation into the collapse of World Trade Center
building 7 on 9/11 was flawed. No
wonder New York residents have launched a High Rise
Safety Initiative to try to protect the safety of those who work or
visit office buildings.
Postscript: Until this issue is resolved through a complete
revision of building codes and architectural and engineering practices, we
recommend that everyone stay out of office buildings. Because if even small
office fires can cause the whole building to collapse, itÕs just not worth the
risk to go inside.