On NOVA's "Why the Towers Fell"

Seen April 30th in the Los Angeles area on KCET, PBS's science series NOVA
presented a compelling hour, titled "Why the Towers Fell." This was a
plain-language translation of the engineering analysis of the WTC disaster.
My friend Carol, watching at 8 PM Eastern Time in New York, called to remind
me to watch it. She didn't need to; I'd marked my calendar a week earlier,
when the program was first promoed.

When I was in New York at the beginning of March, Carol and I had discussed
some of what was then being said in the press about possible deficiencies in
the construction of the buildings. The construction trades in New York are
well known to have been Mob-influenced down through time. There is no reason
to think the late 1960s and early '70s, the years when the Trade Center was
being built, were any different. And while the official report findings on
the disaster recommend certain changes in construction techniques and
materials, the report doesn't seem to suggest that building materials were
below code. In our minds, though, the jury is still out on this point.

What the "Nova" program did in great detail, and very well, was show the
sequence of events within the structure of the two buildings when they were
attacked on September 11th. Video shot on that morning was used to amplify
the things we already knew, and shed new light. Early in the show we're shown
footage of the hole made by the plane that pierced the North Tower.
Skillfully enlarged and probably enhanced, it was possible to see where the
right wingtip had almost surgically entered the facade. The same shot was
held long enough to allow us to look over the damage in detail; on the left
we could clearly see an upright beam twisted at it's breaking point, already
leaning many degrees off square only moments after the plane had struck the
building.

The plane that was flown into the South Tower did not strike it on center,
but rather more toward the building's outer edge. This was important, because
less of the core of the building was damaged, and the building therefore
collapsed because of a different set of forces acting upon it. NOVA was able
to show us this through a remarkable set of 3D animations, used to illustrate
this and many other features of the Towers' construction and failure. Using
simply modeled black & white animations, we follow each plane as it
approaches the WTC and, as it pierces the mass of the building, the camera
travels up and changes our point of view. We now are looking down through the
roof of the building; we see the outer walls and the building core, with the
damage on each floor clearly visible.

3D rendering also provides us with an understanding of how the core and the
facade related to one another- the design of the Towers was radical in that
the outside of the building was load-bearing, in order to provide more
column-free floor space. As we see how the floorspace was designed, animation
shows us rows of floor joists, how they joined the core to the facade, how
they held up the floors- and how they failed.

Perhaps the most telling 3D rendering seen in the program was the simplest -
it concerned fireproofing. In March there had been talk that the sprayed-on
fireproofing used in the WTC was not thick enough. What animations
illustrated was that the nature of the material itself was a problem: the
force of the impact of the planes was enough to blow the fireproofing off
anything it covered. This left the buildings' structure at the mercy of fires
hot enough to melt steel. Animation showed the blast-force moving over the
floor joists and blowing the fireproofing in to tiny gray bits.

When television addresses our questions with such directness and clarity it
performs it's very highest and best mandate: to serve the public. New
Yorkers-Americans-still have so many questions about September 11th that are
beyond our ability to even frame in words. The video and perhaps especially
the animation used here took us into a space that we needed to see in order
to be able to understand. It is to PBS's credit, too, that some of the 3D
graphics and animations appear on the web pages relating to this show. The

text presented on the web also enlarges on points made on the broadcast,
which is an intelligent way for NOVA- produced by Boston's powerhouse WGBH-
to present more of the facts.

"Why the Towers Fell" is, of course, compelling and intense TV. But we are
well served by the work because it takes the worlds of architecture,
engineering and design and makes them so usefully clear to all of us who
still yearn so desperately for answers that address our terrible loss.

About the Author

Nancy LeMay is a five-time Emmy winning broadcast designer who has worked both in New York and LA, in network and local. She is a teacher and a painter as well. You can reach her through her website, www.Nancylemay.com and by email at NancyLeMayCo@aol.com