9/11 was sort of an inside job by the architects.
Built during the height of the cold war, every mega construction project would have had to address what would happen if attacked. There had been a number of massive skyscraper fires already and even much smaller buildings had no way to effectively douse the flames. Imagine a massive raging inferno towering above a dense population centre for weeks or months or who knows how long. It would have been an even worse outcome. The health and mental health effects would have been incredibly devastating. A decision had to be made. A structural, engineered weakness to very hot flames was built in to make the towers implode on themselves, snuffing out the flames.
It would have been a tough call to make. Like the trolly problem, do you engineer it to save the occupants? Or the potential health of the rest of the city?
It makes sense to me to keep quiet about it after the fact. The architects did what they had to do and some people would not agree with their decision. Therefore due to 'national security' or whatever it's best to just keep quiet. I've held on to this theory for a while but I think it's been long enough to discuss it.
This makes way more sense than any other crackpot 911 theory I’ve ever heard.
What if was less a structural weakness than actual demolition charges built into the superstructure of the building that few knew about that could be used in just such an event?
Different materials burn at different temperatures, and a raging inferno near the top wouldn’t affect structural members near the bottom, so a fire might not be guaranteed to trigger the weakness, but charges could be placed to guarantee the outcome if the worst happened.
Would explain SO much of the “evidence” that 911 conspiracy theorists talk about - the smell of chordite, the flashes in the windows, the clean collapse, that whole “the decision was made to ‘pull’ [building 7]” but no way they could have placed charges that quickly in that situation thing…
Then, this begs the question - What other structures might be similarly equipped?
Then, this begs the question - What other structures might be similarly equipped?
I also think this theory is plausible, and if it is true I assume it's stayed under wraps precisely because they didn't want future terrorists to be able to just trigger the conveniently pre-installed explosives.
Not really. It is more that no one really thought that this would be something you had to design for.
Now, a bomber hit the Empire State Building at it survived. So, you could design a building to withstand a plane hitting it. The problem is that the Empire State Building is heavy; it is probably the last skyscraper whose design was controlled by dead load.
There had been studies into failure of buildings after the Oklahoma City Bombing; some of the fruits of that research led to designs which were installed in the Pentagon by 2001. However, for most buildings, it wasn't considered to be worth it. This includes skyscrapers both in the USA and around the world.
A * B * C is generally considered below the cost of making most buildings plane impact resistant, so they don't do it.
The other thing is, both towers were plane impact resistant. Both of them took dead square hits from airliners and remained resolutely standing afterwards. What it turned out they were not proof against was an ongoing raging inferno inside that was hot enough and carried on long enough to weaken their critical structural elements.
If the planes had not been laden with fuel and/or if it had not ignited for whatever reason, the towers probably would not have collapsed. They probably wouldn't have been readily repairable, though, so then the question would be what to do with two massive skyscrapers with giant holes in the middle of them. They'd probably have to be demolished eventually anyway. Said demolition would have killed far fewer people.
The point was that New York City saw a large plane hit one of its largest buildings. The failure mode was known. It just happened to be that no one cared to design for that failure mode later.
The last plane crash into a building in NY before 2001 was back in 1946, when a transport aircraft from the US Army Air Forces flew into 40 Wall Street.
That was 55 years before 9/11, and 20 years before construction of the twin towers was started, it was believed to be a solved problem, which in context wasn't that unreasonable.
Checkout the Well There's Your Problem podcast about the WTC buildings and the attack.
It is three hours long, quite rambly and full of dark humor, but digs quite deep into the time the towers where constructed and the issues that it caused during the attack.