No, and for WTC1 it looks like NIST’s proposal is wrong. From the video record, the antenna began descent before the perimeter failed, and the antenna was near the centre of the roof and thus over the core, so it looks like the core failed first, whereas NIST claim the perimeter failed first.
But I am sure that structural failure due to damage and fire was possible; NIST tested their proposal with a full-scale mock up, and it nearly worked; the floor systems sagged, but not enough to cause structural failure. Ultimately, anything can break, and it is likely to break in a way that hasn’t been thought of, and don’t trust any engineer who tells you otherwise; he’s over-confident. NIST made their mock up for the test, so it was brand new, whereas the Twin Towers had stood there for decades, suffering metal fatigue, rusting, modification and whatever else. And we can’t be sure it was ever constructed to full specification, or that the steel components didn’t have manufacturing weaknesses. And as I said before, the towers could have become overloaded with contents of excessive weight.
Failure is always possible, but the art of engineering is to make failure as unlikely as you can. But it ultimately comes down to thermodynamics – every structure suffers random changes over time, there are infinite ways that changes can cause failure, but theres’s only one way a structure can avoid failure which is not to change too much, so ultimately luck and time are against you. Your structure will fail eventually, even half of Stonehenge has fallen down. Smashing an aircraft into a structure and setting it on fire speed up the rate of change, and thus hasten failure.
Structural failure is proven, by the photographic and video record of gradual deformation of the buildings at the damaged zones prior to collapse, and by the wreckage, which includes some vertical column members bent double.
I rule out pre-rigging with explosive demolition systems as the initiator of structural failure because, in both cases, structural failure occurred at the damaged zone, but that’s where any pre-rigged system would have had to operate properly, despite aircraft impact damage and extensive fire.
I don’t rule out assistance by explosives placed in or near the damaged zone after impact of the aircraft, and here’s a little snippet you probably haven’t seen on Truther sites.