In sheepish defiance of Glenn's admonition, I'd like to clarify from my personal expertise some misconceptions Derbig Mooser aired about the structural integrity of the WTC.

Those buildings were not constructed in the traditional manner of steel skyscrapers. The lacy window mullions visible on their surface were actually structural, and bore a considerable amount of the buildings' weight. In short, they were like birdcages, with light but frequent vertical members, and the interiors were designed without the usual 16' - 20' on center columns generally used in such structures. One steelworker described them as "90% air."

Further, they lacked the hardened core of poured concrete one often observes in buildings under construction, which surrounds the elevator and stairwell chases. They had only a ring of columns of steel, and the stairway walls were nothing more than sheetrock, much of which popped off upon impact and blocked passage as it littered the stairwells.

Much of these deficiencies can be laid to the desire to make them the "tallest buildings in the world," which helped accomplish the difficult task of getting them approved politically and in the minds of the public.

The port authority, which was not subject to ordinary building codes, took similar liberties in fireproofing the steel members, switching midway from an asbestos-based product to an untested substitute, a lot of which sloughed off in the rain as they were erected.

Because of the susceptibility of steel to lose strength in fire, older steel buildings had always had large columns at regular intervals, typically surrounded by a layer of masonry to protect them from heat and offer redundancy in the form of compressive strength.

When a plane hit the Empire State Building during WWII, these redundancies, and the heft of the columns, sliced up the plane, and the resulting fire failed to distort the columns, wrapped as they were in masonry.

The WTC, on the other hand, offered only token resistance to penetration with its skinny outside columns, as anyone watching the planes slice right in can observe. Then, only a center ring of columns, inadequately fireproofed, bore the weight, which was too great and unstable to be supported by the rest of the "birdcage."

The "90% air structure took it from there, straight to the ground.

Derbig, while any building might "seem fine" under ordinary circumstances, ther are those that are unable to stand extraordinary stresses, due to, generally, lack of redundancy.

If you're interested, I recommend "The Skyscraper," by Paul Goldberger; "Twin Towers," by Angus Kress Gillespie, "The Assasination of New York," by Robert Fitch, and "Will They Ever Finish Bruckner Boulevard?" by Ada Louise Huxtable. There's also a book called "Why Buildings Fall Down," which is so useful that I've lent it out to a contractor for whom I design, so I can't tell you the author at the moment.

PS... I'm no lady, as many here can attest. Please make a note of it.

ShawnB, I have a set of the plans in front of me, and I'm fully aware of the 47 (inadequately fireproofed) central columns.

But given what I know about fir codes and lateral (shear) forces, the WTC was built based on too many rosy scenarios, due to a desire for unencumbered rentable space, as well as a need to save money on steel. The floor truss systen was similarly untried, and structurally suspect, particularly because of its long spans. It failed miserably as well. I could never get such a thing passed here.

Further, the ability to withstand high winds is a function of ductility and structural lightness. Indeed, a lab was set up in Eugene, Oregon, home of my alma mater, to test people's ability to tolerate movement, and the potential "seasickness" effect that would impact rentability of the WTC, since such a ductile structure had never before been contemplated. More steel was specified to satisfy psychological needs, after the green eyeshades and sliderule boys approved less.

My argument has nothing to do with 9/11's origin, but was merely meant to point out that, if someone wanted to pick a building that would be easy to tip over, WTC would be not just a good bet, but a sure thing.

Derbig, by that standard, you indeed show every indication of not tipping over. And with your ample armor of leather even that probably would leave you unscathed.

Redundancy: Good for buildings; bad for people.

WT, structural engineering, as I'm sure Pedinska could explain, is the key to holding everything in its place.

And hard hats are just as effective in hiding curlers as any turban or fur-trimmed hood, and the curlers provide an additional layer of protection, to boot. (No references to Condi at the moment...)

WT... I share you lament that Democrats can make a terrific mess, but at least they don't steal the silverware.