Do you think the 9/11 hijackers knew that the WTC buildings would collapse?

[u/JMRooDukes808]

I really don’t know where else to ask this. There is obviously an overload of information about the event itself online, but one thing I can’t find out is if the hijackers intended to, or knew that the WTC buildings would collapse. Do you think they just planned on the impact and fires to be the extent of the damage caused? As far as I know, no steel structure buildings in history had collapsed from fire at that point, so it makes me wonder if they actually “succeeded” in their plan more than they intended.

Edit: no conspiracies please, that was not the point of my post

[u/Hoppie1064]

US forces found a tape in November 2001 that they released the transcript for in December 2001. You can read an English transcript here.

It includes predictions that were made of what the terrorists thought would happen, including bin Laden's himself.

UBL: (...Inaudible...) we calculated in advance the number of casualties from the enemy, who would be killed based on the position of the tower. We calculated that the floors that would be hit would be three or four floors. I was the most optimistic of them all. (...Inaudible...) due to my experience in this field, I was thinking that the fire from the gas in the plane would melt the iron structure of the building and collapse the area where the plane hit and all the floors above it only. This is all that we had hoped for.

In other words, bin Laden thought they might reach every floor above where the plane hit on each tower, but not the collapse of the entire towers.

[u/bouncypinata → u/Hoppie1064]

Imagine the damage if it toppled sideways rather than falling within itself.

[u/damnedifyoudo_throw → u/bouncypinata]

One of the early ideas had been to knock one tower into the other.

The science of “pancaking,” which is ultimately what happened (structure weakening and putting pressure below it, increasing weight until the whole thing fell straight down) was basically unknown and unanticipated. The logic of sending firefighters was that they might be able to control the blaze and save people.

[u/quantum1eeps → u/damnedifyoudo_throw]

Yes, it’s been seen and studied since but not observed previously to 9/11 (progressive collapse by fire)

[u/SensibleChapess → u/quantum1eeps]

Seen where? The Chinese TV tower was of almost identical construction and burned from top to bottom for many, many, hours.

It was totally consumed... the steel frame remained almost unscathed and the building was rebuilt around the original, unaffected, steel.

The three towers that collapsed remain the only three steel framed buildings to have ever collapsed in history.

What's even weirder is, of course, that three buildings collapsed but only two were struck.

Did you know that in the aftermath over 2000 architects and engineers signed an affidavit stating it was against the laws of physics for the buildings to have collapsed in the way that they did?