[laconas]

"But the eventual collapse of the twin towers was so predictable that the order should have been given to withdraw emergency services within an hour, said Professor Knapton. He watched in horror, knowing the building would fall within two hours. The hundreds of dead firemen and police officers should simply not have been there, he said. "

That's wonderful monday morning quarterbacking by so called experts, but the reality is nobody expected the buildings to collapse. The NYFD has the best structural engineers at their disposal, and yet many firefighters died, suggesting this was never thought to be possible. Totally un-expected.

Simply, this is an event that has never happend before and nobody knew what would happen.

I would even go as far to say that the poeple who planned this terrorist act never expected the buildings to collapse.

For sure, there was always a possibility of a total structural failure from heat, but in this case--the buildings collapsing was a total surprise to all.

For the record, steel is severely weakend at 800C, but it does not melt into a liquid, or semi-liquid form at this temperature.

[imberedux]

                 Asbestos Could Have Saved WTC Lives

                            Friday, September 14, 2001
                            By Steven Milloy



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                 Asbestos fibers in the air and rubble following the collapse of the World
                 Trade Center is adding to fears in the aftermath of Tuesday’s terrorist
                 attack. The true tragedy in the asbestos story, though, is the lives that
                 might have been saved but for 1970s-era hysteria about asbestos.

                 Until 30 years ago, asbestos was added to flame-retardant sprays used to
                 insulate steel building materials, particularly floor supports. The insulation
                 was intended to delay the steel from melting in the case of fire by up to four
                 hours.

                 In the case of the World Trade Center, emergency plans called for this
                 four-hour window to be used to evacuate the building while helicopters
                 sprayed to put out the fire and evacuated persons from the roof.

                 The use of asbestos ceased in the 1970s following reports of asbestos
                 workers becoming ill from high exposures to asbestos fibers. The Mt. Sinai
                 School of Medicine’s Irving Selikoff had reported that asbestos workers had
                 higher rates of lung cancer and other diseases. Selikoff then played a key
                 role in the campaign to halt the use of asbestos in construction.

                 In 1971, New York City banned the use of asbestos in spray fireproofing. At
                 that time, asbestos insulating material had only been sprayed up to the 64th
                 floor of the World Trade Center towers.

                 Other materials were substituted for asbestos. Though the substitute sprays
                 passed Underwriters Laboratories’ tests, not everyone was convinced they
                 would work as well.

                 One skeptic was the late-Herbert Levine who invented spray fireproofing with
                 wet asbestos in the late-1940s. Levine’s invention involved a combination of
                 asbestos with mineral wool and made commonplace the construction of
                 large steel framed buildings. 

                 Previously, buildings such as the Empire State Building had to have their
                 steel framework insulated with concrete, a much more expensive insulator
                 that was more difficult to use.

                 Levine’s company, Asbestospray, was familiar with the World Trade Center
                 construction, but failed to get the contract for spraying insulation in the World
                 Trade Center. Levine frequently would say that "if a fire breaks out above the
                 64th floor, that building will fall down." 

That wasn't "Monday Morning", that was decades ago.

[_Jim]

but the reality is nobody expected the buildings to collapse.

Funny, that's *not* what the experts are saying ...

The NYFD has the best structural engineers at their disposal,

That's NOT to say they were at their disposal that particular morning - is it?

I don't imagine that guys like you understand the concept and spec'ing of the fire endurance of a structure - do you?

Even common sense would dictate that something would happen - SOONER OR LATER ...

[Slyfox]

Why did the World Trade Center collapse like a telescope? At the very top of both the towers were huge concrete anti-sway stabilizers which were computer-controlled and kept the towers from swaying and causing people to feel nauseous. Those concrete blocks had to be much heavier than just a few floors of concrete in order to do the job. The towers imploded from the top, a first time ever event, because it could not handle the weight of a 757 plus 24,000 gallons of burning jet fuel and a disconected anti-sway stablizer. Those concrete blocks on top acted as huge pile drivers.

SWIRSKY: I imagine, when I saw the pictures of the implosion of the building, it looks like the fuel must have leaked to the core of the building, and from there it was the massive explosion that caused the building to collapse. So it was something completely unforseen, as far as the design was (concerned).

So, even one of the designers of the WTC has no idea why it impolded the way it did. A melting core would not have caused an implosion. Something very heavy at the top would've caused a telescoping implosion. A 'melting core' would've caused the structure to fall over rather than implode.

It was as if the top of the building was acting like a huge pile driver crashing down on the floors underneath." said structural engineer Chris Wise.

The question is, will anyone take note of this fact? How will they rebuild the towers?