# 9/11 conspiracy reality: How would/could a "diabolical structural engineer" demolish the WTC? **URL:** \ **Category:** Factual Questions\ **Created:** [July 4, 2019, 9:43pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538 "2019-07-04T21:43:41Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [July 5, 2019, 5:13pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/21 "2019-07-05T17:13:53Z")
> [@Gray\_Ghost](#): > > Ramzi Yousef et al came close in 1993. Just how close is a matter of some debate. > > [1993 World Trade Center bombing - Wikipedia](https://en.m.wikipedia.org/wiki/1993_World_Trade_Center_bombing) > > Make the device something like 5 times the size, with higher brissance explosives like e.g., PETN or HMX, with better tamping and placement, and maybe he could have undermined the structure. He did not even come close to accomplishing his goal. If that was a feasible way to bring down buildings, then that would be one of the ways demolition experts would bring down buildings. ---
**Author:** ![Tamerlane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tamerlane/32/7602_2.png) [@Tamerlane](https://boards.straightdope.com/u/Tamerlane)\ **Post date:** [July 5, 2019, 5:16pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/22 "2019-07-05T17:16:32Z")
> [@Gray\_Ghost](#): > > Tallest implosion looks like a condo tower on S. Padre Island. 470 feet. ~One third the height of WTC 1 and about ~one tenth the mass, done in 2009. In other words the WTC would by comparison be an implosion of insane size, which has never come close to being attempted. ---
**Author:** ![Gyrate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gyrate/32/3588_2.png) [@Gyrate](https://boards.straightdope.com/u/Gyrate)\ **Post date:** [July 5, 2019, 5:22pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/23 "2019-07-05T17:22:35Z")
> [@Czarcasm](#): > > He did not even come close to accomplishing his goal. If that was a feasible way to bring down buildings, then that would be one of the ways demolition experts would bring down buildings. Well, there’s “bringing down buildings” and then there’s “bringing down buildings in a controlled manner”. Just because a particular method will destroy a building doesn’t mean it’s a useful method. But parking explosive-filled vans in a basement is probably not one of either type of method. ---
**Author:** ![Gray\_Ghost](https://avatars.discourse-cdn.com/v4/letter/g/c0e974/32.png) [@Gray\_Ghost](https://boards.straightdope.com/u/Gray_Ghost)\ **Post date:** [July 5, 2019, 5:28pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/24 "2019-07-05T17:28:53Z")
> [@Tamerlane](#): > > ~One third the height of WTC 1 and about ~one tenth the mass, done in 2009. In other words the WTC would by comparison be an implosion of insane size, which has never come close to being attempted. And probably nowhere near other structures too, unlike WTC 1 and 2. There are taller structure that have been imploded, thinking very large industrial chimneys/exhaust stacks, but they’re nowhere near anything you’d worry about debris hitting either. For unwanted structures that are near things you’d like to not break, they get disassembled in place. Which sounds hideously expensive. Czarcasm, I think you’re missing a few pieces in your inferential jump there. One big difference between Yusef and, say, Controlled Demolition, Inc., is that Yusef didn’t care if anyone got hurt by his bomb. Rather the opposite, really. He didn’t care about fly rock. He also didn’t care if the building fell sideways into something else. With succssfully undermining one wall, it likely would have done just that. CDI, wants the building to fall straight down. They do care what else they destroy, and are liable when that happens. Just a few reasons why CDI et al, take down buildings the way they do, and not by a 6 ton hunk of PETN in the basement. Not because 6 tons of PETN can’t take a skyscraper down. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [July 5, 2019, 5:59pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/25 "2019-07-05T17:59:56Z")
Why not speculate that terrorists used a mini black hole to bring it down? Do you know what it would cost to manufacture six tons of PETN? Can you even imagine the dangers involved in manufacturing six tons of PETN? BTW, there is no container on Earth that would be able to direct that much PETN so that it looked the way the World Trade Center looked afterwards. ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [July 5, 2019, 6:14pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/26 "2019-07-05T18:14:59Z")
> [@Czarcasm](#): > > Why not speculate that terrorists used a mini black hole to bring it down? Do you know what it would cost to manufacture six tons of PETN? Can you even imagine the dangers involved in manufacturing six tons of PETN? BTW, there is no container on Earth that would be able to direct that much PETN so that it looked the way the World Trade Center looked afterwards. You seem to be missing the point. I am not saying using explosives in the basement will make the rubble look like 9/11. I’m saying it could bring down a building. I’m not even sure where you’re getting that. What I’m saying is, if terrorists wanted to bring down a building like the WTC, they don’t need elaborate CT plans with hidden explosives and fake(?) planes, they can just blow it up. If it took out only a chunk and the whole building doesn’t fall down like it did on 9/11, that’s even better from a terrorist POV. Now there’s all this mess to clean up. It would take months and all the other buildings would have top be kept empty for an indefinite time. And everyone would be worrying if or when the remaining part is going to fall, and where. ---
**Author:** ![Gray\_Ghost](https://avatars.discourse-cdn.com/v4/letter/g/c0e974/32.png) [@Gray\_Ghost](https://boards.straightdope.com/u/Gray_Ghost)\ **Post date:** [July 5, 2019, 6:26pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/27 "2019-07-05T18:26:51Z")
> [@Czarcasm](#): > > Why not speculate that terrorists used a mini black hole to bring it down? Do you know what it would cost to manufacture six tons of PETN? Can you even imagine the dangers involved in manufacturing six tons of PETN? BTW, there is no container on Earth that would be able to direct that much PETN so that it looked the way the World Trade Center looked afterwards. Oh, I dunno. What percentage of a nation state’s monthly production of munitions is represented a few tons of military high explosives? Fairly small, I’d wager. Not like countries like Libya or Iran have ever used the diplomatic bag to ship ordnance before. As for tamping issues, use a bigger truck. Use multiple trucks. It’s a matter of engineering at that point. If your point is that such a method would not result in a collapse identical to how WTC 1 collapsed, I agree. But I think it could have undermined the structure sufficiently to get it to fall. And with that, I’m done talking with you. Go argue with someone else. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [July 5, 2019, 6:33pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/28 "2019-07-05T18:33:32Z")
> [@Gray\_Ghost](#): > > Oh, I dunno. That’s right. Six tons of PETN? Where did you get that figure from? Who proposed that you could do it with six tons of PETN? ---
**Author:** ![Helmut\_Doork](https://avatars.discourse-cdn.com/v4/letter/h/e8c25b/32.png) [@Helmut\_Doork](https://boards.straightdope.com/u/Helmut_Doork)\ **Post date:** [July 5, 2019, 6:46pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/29 "2019-07-05T18:46:40Z")
Note to OP: any sensible question with any reference whatsoever to any conspiracy theory is going to get heated responses from posters who want to shoot down any possibility that said conspiracy was possible, and very few relating to the answer of the actual question. Reposting same basic query without any mention of WTC will net you more fact based responses! ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 5, 2019, 6:48pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/30 "2019-07-05T18:48:21Z")
> [@Czarcasm](#): > > That’s right. Six tons of PETN? Where did you get that figure from? Who proposed that you could do it with six tons of PETN? According to [this](https://web.archive.org/web/20050316140649/http://msnbc.msn.com/id/3069653/), the architect of the WTC testified that even the amount of explosives used by the conspirators in 1973 was capable of bringing it down if it had been better placed. > [@](#): > > But it was a close call. Later, the WTC’s architect would tell jurors that if the van had been left closer to the poured concrete foundations, they would have succeeded. The tower would have fallen. Do you have more expertise on the issue than the architect? ---
**Author:** ![Suburban\_Plankton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/suburban_plankton/32/219_2.png) [@Suburban\_Plankton](https://boards.straightdope.com/u/Suburban_Plankton)\ **Post date:** [July 7, 2019, 2:46am UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/31 "2019-07-07T02:46:56Z")
> [@Just\_Asking\_Questions](#): > > You seem to be missing the point. > > I am not saying using explosives in the basement will make the rubble look like 9/11. I’m saying it could bring down a building. I’m not even sure where you’re getting that. > > What I’m saying is, if terrorists wanted to bring down a building like the WTC, they don’t need elaborate CT plans with hidden explosives and fake(?) planes, they can just blow it up. If it took out only a chunk and the whole building doesn’t fall down like it did on 9/11, that’s even better from a terrorist POV. Now there’s all this mess to clean up. It would take months and all the other buildings would have top be kept empty for an indefinite time. And everyone would be worrying if or when the remaining part is going to fall, and where. No,I think that you’re the one missing the point…it wasn’t _terrorists_ that brought down the WTC with a controlled explosion, masked by a plane crash, it was _ **The Government!!!1!** _. If it was terrorists, they would have just tried something simple. like blowing it up…or crashing a 400,000 pound hunk of metal loaded with 20,000 pounds of jet fuel into it. And I think it’s worth noting here that even in the case of the very much \*uncontrolled \*demolition, those buildings came down pretty much perfectly. That in itself is a testament to the engineering that went into their construction. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [July 7, 2019, 3:33pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/32 "2019-07-07T15:33:43Z")
> [@Colibri](#): > > Do you have more expertise on the issue than the architect? I would never contest him on what it would take to raise a building, but I would consult a demolitions expert if I wanted to know how to raze it. ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [July 7, 2019, 6:47pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/33 "2019-07-07T18:47:36Z")
> [@Suburban\_Plankton](#): > > No,I think that you’re the one missing the point…it wasn’t _terrorists_ that brought down the WTC with a controlled explosion, masked by a plane crash, it was _ **The Government!!!1!** _. > > If it was terrorists, they would have just tried something simple. like blowing it up…or crashing a 400,000 pound hunk of metal loaded with 20,000 pounds of jet fuel into it. So, you’re saying it’s typical government bureaucracy? They make it too complicated? I can understand that. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 7, 2019, 7:41pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/34 "2019-07-07T19:41:41Z")
> [@Czarcasm](#): > > I would never contest him on what it would take to raise a building, but I would consult a demolitions expert if I wanted to know how to raze it. So you don’t know yourself what it would have taken to bring it down. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [July 7, 2019, 7:44pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/35 "2019-07-07T19:44:03Z")
> [@Colibri](#): > > So you don’t know yourself what it would have taken to bring it down. No, I obviously don’t, since I have already said I would defer to someone who knows what it takes to bring down buildings-a demolition expert. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 7, 2019, 8:17pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/36 "2019-07-07T20:17:21Z")
> [@Czarcasm](#): > > No, I obviously don’t, I’ll bear this in mind with regard to your further comments in this thread. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [July 7, 2019, 9:11pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/37 "2019-07-07T21:11:41Z")
> [@Colibri](#): > > I’ll bear this in mind with regard to your further comments in this thread. Just give me the same consideration as you do all the other non-experts in the field that are posting in this thread. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [July 7, 2019, 9:11pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/38 "2019-07-07T21:11:53Z")
> [@Leo\_Bloom](#): > > Any examples of the biggest real-life demolition projects was my first query. There can’t be a matching example, because the WTC had the unique property of having low safety margin of 100%. That is, the breaking point of all the structure was only double the stress that each bit was already taking. I fear this just feeds the conspiracy theory … “oh the building was unique in being weak, it was a liability , he was going to have to pay to demolish it , as opposed to being paid when it got demolished… so thats why he faked a terrorist attack.” It wasn’t brought down by an explosion, the plane caused a large fire inside and that fire soaked heat into the structure over the half hour that raised the steel up through 400 Celcius… which was just warm enough to soften it, and very approximately, halve its strength… so if the safety margin became lower than 0%, which means structure broke. So other structures would have much larger explosions. While video of other sky scrapers would show that the explosion to demolish it would have to be a huge explosion that would be visible, even among the clouds of smoke from the fire, the shrewd conspiracy theorist would see you putting up an irrelevant video , and say that therefore, the conspiracy theorist is right, or bright, or something… So for an example that matches the collapse… Hindenberg should have sat on the ground as a big sausage , if it wasn’t structurally weakened. Pancake stack buildings from earthquakes. (the difference is that the floor of the buildings in the pancake stacks of a five storey building are extremely strong, relative to the columns. The WTC floors are insignificant compares to the columns so the collapse pile only shows large sections of wall and column sticking out of the pile of unrecognisable mess. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [July 8, 2019, 12:06am UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/39 "2019-07-08T00:06:38Z")
> [@Leo\_Bloom](#): > > 1. So, could anyone supply a back-or-the-envelope sketch of such a diabolical plan using conventional modern techniques to bring the WTC down? Keep it general enough so you don’t blow your cover to the FBI.[sup]\*[/sup] Well the obvious way would be to start a big fire on the 93rd/99th floors. It wouldn’t require any special skills, and wouldn’t require any special explosives. I’m not familiar with the conpiracy theories, so I don’t know what the objection is. If the objection is “fire couldn’t do that!” (may I just say DUH), then a “diabolical” approach would be to remove the protective insulation and concrete, so that fire _could_ do tha on the required time scale. Absent a big impact, jackhammers could be used. If that _still_ doesn’t fit the scenario, cutting torches could be used to cut the steel until most of the safety margin was removed, so that it was perhaps only a 100% safety margin, the concrete and other fire insulation could be cracked, and _then_ a fire could be started. One of the big reasons fire isn’t often used to destroy buildings is that it is uncontrollable. Another reason is that destroys the materials. If we take away the desire to have a controlled demolittion, and to salvage the materials, arson seems like a very reasonable way for a diabolical technologicly educated conspiricist to take down a building. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [July 8, 2019, 12:34pm UTC](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538/40 "2019-07-08T12:34:13Z")
> [@Melbourne](#): > > Well the obvious way would be to start a big fire on the 93rd/99th floors. It wouldn’t require any special skills, and wouldn’t require any special explosives. ??? The building was designed to survive a hit from a jet whose size was common at the time of construction. It wasn’t designed to withstand a hit from later larger jets carrying more fuel.\* Think about this. How much fuel is in a 1973 era jet vs. a 2001 era jet? So, first of all, it’s going to take a lot of fuel. A _lot_. Secondly, there’ the issue of removing the insulation which the crashes did a good job at. So you need a group of explosions that will do the job over an area the size of a large plane hit. And a _lot_ of widespread fuel catching fire. All in the exact spot of the plane hit. Where are you going to hide all that fuel in a building that people work at regularly? You don’t want people going “Gee, why are they 15 thousand gallons worth of barrels on these two floors? Isn’t that going to cause load/floor problems?” It is so incredibly absurd to try and plan this all out and keep it secret when the planes themselves will do the job just fine. If you can hit the buildings with large jets, that’s it. Not a single thing needs to be added. - Early on, they called one of the architects of the WTC and asked him what might happen with these planes hitting them. He did a back of the envelope calculation using the higher weights and fuel capacities and called them back: They’re coming down, clear everyone away. [Previous page](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538.md?page=1) [Next page](https://boards.straightdope.com/t/9-11-conspiracy-reality-how-would-could-a-diabolical-structural-engineer-demolish-the-wtc/836538.md?page=3)