CarolC,

The picture you show (black and white) of some steelwork is at such an early stage of construction, they weren't even above lobby level!. I told you that I did not know whether the box-beams were concrete-filled, I said that they probably were, this being a normal construction method.

That the core had a steel *frame* is not disputed - what do you imagine is meant by "steel reinforced structure"?

But tell me this - if they made liftshafts and stairwells and corridors without poured concrete, does that not shoot your arguments down? If the core had no curtain walls to protect it from fire and blast?

The core has sweet FA to with the collapse anyway - as I explained to you - the floors and exterior load-bearing columns were cut, the floors were unsupported, the fire degraged the remaining load bearing steel when the floors started to collapse they tore down the building around them and including whatever core structure was there.

I know that this may come as a shock, but 1,300ft concrete or steel or jam cores that were designed to be held up by, while holding up, a mutually supportive structure (of floors and exernal columns) won't survive the floors and columns being torn down around it.

Whatever the core was made from, it was buggered when the planes crashed - because people weren't able to escape through it.

Now I am not getting drawn any further into your private hell.