Skip directly to content

Facts of 9/11---do they add up?

  • Heather_118's picture
    Facts of 9/11---do they add up?
    Heather says (30 May '10)
    • Jet Grade Kerosene burns at 1200 F and it takes 2750F to melt steel. Melting steel is only possible under blast furnace conditions or thermit, which is used for demolitions.

    • Did you know that in all of history, a steel building has never collapsed due to fire? Steel, glass, and concrete cannot burn.

    • WTCs collapsed STRAIGHT down, directly into the path of MOST resistance (building that falling due to an event like this would fall towards the path of LEAST resistance) and that the north tower fell in 9 seconds and the south tower fell in 11 seconds, which is free fall speed, which does not coincide with the gov'ts theory of pancake scenario. I was watching this LIVE on TV----those towers WERE demo'd!!!!

    • Building 7 was the third building that fell, it was a pulled demolition at the request of the WTC owner. Pulled demos take weeks to set up, and yet this tower fell within hours of the other buildings.

    • Did you know that Building 7 was the nations emergency command center and contained all of the CIA and FBI records?

    • Did you know that the WTC was a financial disaster that was losing millions of dollars every year and the new owner had purchased the WTC approx 90 days before 9/11 and insured the center for millions more than its' actual value, oh, and he DID collect profitably after 9/11.

    • In the FBI's list of supposed attackers, not one of those men were Iraqi, Afganistan or Iranian?

    • On Sept 11, Donald Rumsfeld conducted a military drill simulating an attack on the WTC twin towers, explaining why jet fighters weren't scrambled--which is a military term for sending fighter jets to negociate an escort or shoot down an enemy plane. I find it hard to believe that our country, one of the most technological nations on the planet, lost the positions of not ONE, but FOUR commercial jets that ended up crashing into buildings at the same location, 20 minutes apart? BOGUS!!!

    • As noted in the SF Chronicle, Mayor Willie Brown was warned NOT to take flight on 9/11.

    • On 9/11 a commercial jet supposedly slammed into our Pentagon, yet, it didn't touch one telephone line/pole, no street lights, no surrounding vehicles, no surrounding structures in direct line of the Pentagon? Have you ever seen wreckage from a Commercial jetliner? There is mass destruction to the grounds all around it. There was also NO evidence of passengers or their belongings at the 'crash site".

    • There were NO airplane parts or passengers found within a mile radius of the supposed 9/11 crash in Pennsylvania.

    Fellow Americans......this is TREASON by your GOVT.

    Just look back on ANY war and you will find the mistruth behind it and the very greedy individuals fueling it.

    They have been lying to us for over 100yrs regarding war and terrorism!!!!!

    I've gathered these facts from all over the place, from newspapers to books, to videos put out there mostly by individuals who are questioning what has happened and why, alot of these people are still trying to figure out what happened to their loved ones on 9/11.

    Please tell me your views and please, please, please, don't call these views crazy or approach them in a negative manner, if you don't agree, just simply state it and why, no need to call people names!!!!

    37
    Filed Under: Community Blog Archive
Heather_118's picture
on Sun, 05/30/2010 - 12:06am
  • Jet Grade Kerosene burns at 1200 F and it takes 2750F to melt steel. Melting steel is only possible under blast furnace conditions or thermit, which is used for demolitions.

  • Did you know that in all of history, a steel building has never collapsed due to fire? Steel, glass, and concrete cannot burn.

  • WTCs collapsed STRAIGHT down, directly into the path of MOST resistance (building that falling due to an event like this would fall towards the path of LEAST resistance) and that the north tower fell in 9 seconds and the south tower fell in 11 seconds, which is free fall speed, which does not coincide with the gov'ts theory of pancake scenario. I was watching this LIVE on TV----those towers WERE demo'd!!!!

  • Building 7 was the third building that fell, it was a pulled demolition at the request of the WTC owner. Pulled demos take weeks to set up, and yet this tower fell within hours of the other buildings.

  • Did you know that Building 7 was the nations emergency command center and contained all of the CIA and FBI records?

  • Did you know that the WTC was a financial disaster that was losing millions of dollars every year and the new owner had purchased the WTC approx 90 days before 9/11 and insured the center for millions more than its' actual value, oh, and he DID collect profitably after 9/11.

  • In the FBI's list of supposed attackers, not one of those men were Iraqi, Afganistan or Iranian?

  • On Sept 11, Donald Rumsfeld conducted a military drill simulating an attack on the WTC twin towers, explaining why jet fighters weren't scrambled--which is a military term for sending fighter jets to negociate an escort or shoot down an enemy plane. I find it hard to believe that our country, one of the most technological nations on the planet, lost the positions of not ONE, but FOUR commercial jets that ended up crashing into buildings at the same location, 20 minutes apart? BOGUS!!!

  • As noted in the SF Chronicle, Mayor Willie Brown was warned NOT to take flight on 9/11.

  • On 9/11 a commercial jet supposedly slammed into our Pentagon, yet, it didn't touch one telephone line/pole, no street lights, no surrounding vehicles, no surrounding structures in direct line of the Pentagon? Have you ever seen wreckage from a Commercial jetliner? There is mass destruction to the grounds all around it. There was also NO evidence of passengers or their belongings at the 'crash site".

  • There were NO airplane parts or passengers found within a mile radius of the supposed 9/11 crash in Pennsylvania.

Fellow Americans......this is TREASON by your GOVT.

Just look back on ANY war and you will find the mistruth behind it and the very greedy individuals fueling it.

They have been lying to us for over 100yrs regarding war and terrorism!!!!!

I've gathered these facts from all over the place, from newspapers to books, to videos put out there mostly by individuals who are questioning what has happened and why, alot of these people are still trying to figure out what happened to their loved ones on 9/11.

Please tell me your views and please, please, please, don't call these views crazy or approach them in a negative manner, if you don't agree, just simply state it and why, no need to call people names!!!!

Forum category: 
Heather_118's picture

Heather_118's picture

Connie, I haven't had much time to read and think about what you've responded with.
I'm sick and I'm so busy at work :(

I will say that I don't think it would be too hard to cover up something like this as it's the gov't we are talking about. They are pretty crafty and keeping the general public out of the loop is fairly easy! Just look at how Bush got us to war---illegally---and what did the citizens do? Nothing! They were/are fearful and angry at terrorism, so they let it happen. Just look thru history (you pointed out many good things) and you'll find a corrupt gov't everywhere!

I was watching tv live that morning too, crying----wondering what this meant for our country. I felt the pain of all those victims, I felt the pain of their families, I felt the pain of the nation, I feared for our soldiers as I knew War was inevitable and I knew it would happen quick.......still, the war had an agenda, however our country did not follow that agenda and made one up of their own.

As far as our gov't shooting that plane down? That was my initial thought, and still think that is possibly what happened. However, lying to the general public about what happened to protect us from the real truth is stupid! Lies never accomplish anything. I think a majority of the US citizens would not even bat an eye if they learned that plane was shot down. My question is.....if they could shoot down that plane, then why couldn't they get to the other planes?

Air traffic controllers have NOT been allowed to talk to the media regarding this issue.
At least nowhere I have found.

I still haven't found anything suggesting that these planes were hijacked with anything else other than a box cutter. I have never been in a hijacking situation, but I'd like to think that a plane full of people could overpower 2 or 3 men with box cutters, even if it meant crashing to the ground. If you know you are going to die anyway, what do you have to lose?

Reactions from Bush didn't even

Connie Jo_3's picture

PSS: Keeping having related thoughts, haha. Let's not forget all those aboard the airplanes, including the Pennsylvania and Pentagon planes...of whom called and spoke with loved ones prior to the crashes. One who was aboard the plane crashing into the Pentagon...was the fiance of a CNN Journalist. Again, more people who would have to be in on the conspiracy, especially related to the theory of the plane not existing that crashed into the Pentagon. The theories of conspiracy are simply not valid based upon the vast number of people required for such a detailed conspiracy plot and success of.

Also, local network stations br FCC law weren't allowed on my Direct TV satellite back in 2001...my locals were provided off the East & West Coasts. My local ABC channel was out of NYC, which is what I was watching when I heard the news of the first plane crash. There were live local reporters on the scene from the NYC channel I was watching, and I saw the 2nd plane crash into TT2 live as it happened, as the cameraman had his camera panned towards the sky showing the first plane crash fire & TT1.

I will never, ever, forget the panic I felt for the people inside, and saying out loud more than once...those people need to get out of those buildings before they crumble! I even told my son this while talking to him on his cell...as he was in transit unable to watch TV & see what was happening. The reporter at one point was talking to an engineer, interviewing him on the scene...and he was explaining to the reporter what was previously mentioned by someone else in this blog...that the TT's were engineered to withstand a plane crashing into them, due to their close proximity to airports, and that if they were to somehow fall, they were designed to fall inward rather than outward to avoid crashing into other nearby buildings. As I heard the engineer say what he did, repeating to my son, I also told him...bullshit, those buildings are gonna go, they need

Connie Jo_3's picture

PS: There were literally 100's of witness', including civilians driving nearby, who saw the jet fly over and into the Pentagon exploding...so again, 100's of more would need to be involved in the conspiracy simply as claiming to be civilian witness'.

Connie Jo_3's picture

I took my time reading through all the posts, considered all that was said prior to posting. I remember when many rumor's began a few years ago related to our government having secret involvement in the attack of 9-11. I spent hours doing research myself, read theory and reason from many sources. I was curious, because it is proven fact that our government has in the past kept dark secret's from us, cover ups...Ruby Ridge, Waco, Pat Tillmans cause of death being friendly fire, not enemy...assination attempts such as on Castro, vote tampering in the Chicago area related to the Kennedy vs Nixon election, Kennedy's involvement with the Mob, their putting him in office, etc.. When the truth comes out, those held accountable always claim it was necessary for the benefit of all in the long run, whatever. I can relate to those who don't trust our government, as I don't trust our government either for good proven reason, so I did my own research on 9-11 conspiracies.

My conclusion then remains my conclusion today. I don't believe our government had anything to do with the 9-11 attacks. Although, I do believe it's highly possible the US Air Force shot down the plane in Pennsylvania for justifiable reasons, but under the circumstances our Government felt it best not to let an already traumatized country know what had to be done to save a majority of lives in DC. As well, I've no doubt pyschologists on the Presidential staff as public relations advisors...told those in power that it would be beneficial for civilians to hear stories of heroism to help us cope emotionally & reduce panic. By telling us those aboard the Pennsylvania flight died so herocially...it was a positive emotional factor to help bring a sense of balance to all the negative emotions going on within the majority of us at the time. It helped us to lower panic levels knowing some fought back and though they died, were successful in saving literally thousands of lives and our White Hous

Heather_118's picture

Teresa

Did you go to the downtown event? I've read up on the secret societies and One World Order. Its been in the works for a very long time,,.........Hitler and Stalin were men who supported the Illuminati, a secret society, which I believe (I'm no expert on this by no means, lol) supported the fact of a 'new man', and are, get this.....BANKERS (didn't our bankers JUST GET BAILED OUT????? and millions of foreclosures ALL over our country are making these banks TITLE HOLDERS ON OUR LAND).

Heather_118's picture

oh and KevRun...I'd love to talk to your friend the NYC cop.......was he there that day? All the more better, I have tons of questions for him and IF he was there, I'd love to thank him for his humanity he showed that day!

Heather_118's picture

http://911research.wtc7.net/essays/thermite/blasting_scenario.html

to anyone interested in my country bashing, here is a very cool link

In all my searching the past few years I have yet to find a good webpage with 'neutral' topics that examine 9/11 from all sides. WELL, I found one today, why I missed it before, who knows..maybe it wasn't there???? But thought I would share. It does seem to dispprove many of my original beliefs surrounding the two planes I had in question, however, it may prove they were not the planes disclosed to the public. Anyhoos, have fun reading--I did :)

Here is the home link, the above link is a very indepth look at the thermite theory and looks at it from ALL angles.

http://911research.wtc7.net/index.html

Heather_118's picture

lol Kevrun, there you go name calling again...
that's OK, really, FEMA has a wooden box with your name on it :)

That Guy's picture

Heather, you have some serious issues with your country. Maybe you should leave!!

I have a friend named Paul, he is a NYC cop, I would love for you to take all your ignorant youtube videos and bullshit conspiracy theory rag writings and sit down with him.

It just makes so much sense.. The government destroyed the WTC, sent out economy into a fucking out of control spiral, and practically made our country a fucking mess...

Fuck, I cant even muster any passion when arguing this absolute stupid shit anymore..

ANGELIQUE LACRISSA's picture

i see your one world order thing happnin but what are you good or evil giver or taker a lil of both
uhhhhhh id never tell ...its a way of thinking would people of diff way come together to believe and make your kids believe or seek the truth ...in either way ya know right from wrong..
ok here was a thought submitted to me hes dead right the mcviey guy did he act alone or were terriosts funding him all along did he just fit a profile cause iminstration had denial......i dontknow we as american have the tv and internet as resources who are ran by billionairs i mean who frekin even knows ...
im always a skeptic but human lives were taken on us soil ....so at the expense of our freedom..

there is a plan maybe not implemented but felt by many who just cant seem to get words out right , however ,

know this when it comes down to it many people will band you cant help but hear the cries in the st...
it has to be a simple way of life taxed to fukin death i guess

kidrockangel's picture

Wasnt Timothy McVey part of a mIlitia. UM NO THANKS

I still dont understand why the Government would want to blow up towers or pentagon. I do understand why they would shoot down a plane. It makes no thanks

teresa_67's picture

I find all this information another reason to do research. Our government is known for so many unjustified actions that the American people do not trust our government. I would guess-a-mate that over 50% of Americans believe the government had something to do with 911. What most people don't understand is the Bilderberg Corporation, Tri-Lateral Commission and Colalition of Foreign Affairs (security 20 council) These groups consist of a few hundred billionaires whom want ONE WORLD ORDER every President since JFK is involved in these organizations. The goal is one world govt with a world population of 1 billion. Funny we currently have over 5 billion people in the world. These folks meet once a year there last meeting was in my home townPittsburgh this past September. They used Nazi Germany tatcis on the people on the streets outside the the downtown perimeter actually in the area as the Hill District(mostly low-income, povery stricken, drug infested, ran down area) The police were dressed in head gear, sheilds, billy clubs, guns, tear gas, marching in step just like Hilters soliders There were about 150 people peacefully protesting ONE WORLD ORDER when here comes this large truck equipped for war with sound equipment that ruptures your eardrums. They actually used it for no real apparent reason. They was no outragous behavior of any type being displayed. The video can be seen on YOUTUBE search security 20 council Sept 2009 Pittsburgh PA> It was unbelievable that these are our own police officers and military payed 4
by our taxes dollars retaliating against the own people for these wicked men and women whom want to run the world. The plans they have for us are real just as stated in the program HAARP, another earthquake in Turkey this is the 4th earthquake in a lil over a month. Either way we Americans are in trouble unless we ban together start talkin 2 ur neighbors discuss all these issues educate everyone u know, then we need a plan. Those p

Heather_118's picture

bobbys boy.....the only thing I feel I can do to change things is to vote responsibly and to teach my children to vote responsibly and to possibly alert other people to ask why? what? who? where? BEFORE sending our troops, our beloved men/women/children/brothers/sisters/uncles/aunts, etc to WAR!

I am seeking the truth, no matter what it is. And I don't think I'm being told the truth about what happened on 9/11

I do support our troops, I do support their families, I just don't support this war. I am from a Military family, I support soldiers with the utmost respect. My father was a Korean War vet and he was very pro military, yet at the same time, he questioned the politics of war, but I also know the demons within that tore him apart and I'm sure as any soldier would find it hard to admit the fears and guilt they hold inside, as when he'd get drunk, he'd open up and tell us stories of his experiences of war and how wrong it can be on so many levels, starting from our leaders in Washington using soldiers as their pawns! I have a VERY open mind and that is why I enjoy having blogs debating these issues. Calling names and being disrespectful isn't a solution to anything, I've learned that in here, lol, and in life in general.

thanks Angel :)

kidrockangel's picture

ok if it wasnt a jet that hit the pentagon, then where is the Jet and all the missing people???? Im confused. AND HEATHER ISNT A MORON... kEV.... AND these convos are kinda fun. better than how i fucked Bob in 5 minutes....lol

Christy_41's picture

add up nothen add up when they crossed our lines and spread our friends and family's blood...no it dont add up..it fuckn hurts every day...when my brothers go to war it hurts when I watch my sister cry for her man it hurts..when her babies dont get to see there daddy for 18 months at a time it hurts..When I wait on theise soldgers right before the go they are all dresses look fearless but the pain and fear in thier eyes is something that cant be hid...!!!!!!! And it fuckn hurts and all I can do is say Thank you!! buy them a beer...!!!!!!!! they Did fly airplanes in we seen it not just on tv lets go talk to brains dad up the raod enough for his windows to blow...
9/11 was terrest..
OKC bombing was a fuckn fruit that killed many weman/children and men...Yes I had friends in that one too some here some never to be found!

Christy_41's picture

Way to go Keven AND Angel.
and my thoughts are 9/11 is one more tragic even that freedom isnt free.never has been never will be,,,God bless all

Heather_118's picture

lol Kevrun

should I close blog comments? perhaps you aren't as smart as you say you are or you would have known that I didn't want people on this blog causing trouble by name calling and so far, you are the ONLY one who has been name calling. You have a right to your opinion as does everyone else and nobody needs to be riduculed, that was not the thought behind this blog.

and how do you know the things I posted are NOT facts? Where did you get YOUR facts? hmmm??? LMAO as I was here when I wrote this blog....if I didn't write it, who did? If you mean that i got my info from a website, video, book, etc, you are right about that, but I didn't have someone else write my blog for me.

You are the one who looks like a moron. Please don't take up space on my blog anymore Kev....unless you have something intelligent to say without pointing out your opinion of someones intelligence. Thanks.

Man, I thought I asked nicely, I did say please, did I not?

ANGELIQUE LACRISSA's picture

i hear ya on gathering up the land before opps too late all the conviennt stores hotels and grocery store are bought up
fukem kev you are smart ASS naw much love and respect.. i pray it never happins again but the likeyhood is greater that it will someday...so what about them 1000 acres i got mine in mississippi unless the gov gets it which overr my fuken dried up long dead fukin body and a few other too, but they steadly trying .....i love your theory... right after that happened i shit yall not now, me and my buddy chris were up it was like 4 am playing cards and watching the news OK they hadnt really put the blame on osbama yet and they flashed a pic of this dirty lookin dude with a scraagy beard now he was riding a fukin dirtbike and they put a bullienton that said if youve seen this man call the fbi.. i remember chris and i looken at each other like wtf that ole scragly sum bitch did all that ..and we disscussed it , at the time no one had thhe blame but i loooked for another storey a pic of this cat even that news storey never found it .....i know we werent that high to this day we both remember seeing it .. this guy way like riding his scooter off in the sunset couldnt believe it thank god wasnt dumb enough but its all a great read.... i really wish more people could get back to the old skool way of thinking just about ways of life basics.....

That Guy's picture

I love these posts, it reminds me how smart I am, and how silly, stupid, and gullible many others are. You see, the first big mistake you make is pawning off this upchuck of information as FACT. These are not facts. Second, you did not write this, therefore not giving credit for this info to the correct loony allows me to direct my opposition directly at you.

So, As far as BULLSHIT 1, Here is some fact for you... Jet fuel burns at 800 to 1500F, not hot enough to melt steel (2750F). However, experts agree that for the towers to collapse, their steel frames didn't need to melt, they just had to lose some of their structural strength and that required exposure to much less heat. "I have never seen melted steel in a building fire," says retired New York deputy fire chief Vincent Dunn, author of The Collapse Of Burning Buildings: A Guide To Fireground Safety. "But I've seen a lot of twisted, warped, bent and sagging steel. What happens is that the steel tries to expand at both ends, but when it can no longer expand, it sags and the surrounding concrete cracks."

"Steel loses about 50 percent of its strength at 1100F," notes senior engineer Farid Alfawak-hiri of the American Institute of Steel Construction. "And at 1800 it is probably at less than 10 percent." NIST also believes that a great deal of the spray-on fireproofing insulation was likely knocked off the steel beams that were in the path of the crashing jets, leaving the metal more vulnerable to the heat.

But jet fuel wasn't the only thing burning, notes Forman Williams, a professor of engineering at the University of California, San Diego, and one of seven structural engineers and fire experts that PM consulted. He says that while the jet fuel was the catalyst for the WTC fires, the resulting inferno was intensified by the combustible material inside the buildings, including rugs, curtains, furniture and paper. NIST reports that pockets of fire hit 1832F.

"The jet fuel was the i

ANGELIQUE LACRISSA's picture

wow that is alot to consider , god bless america

ANGELIQUE LACRISSA's picture

omy gosh i thought about it like that ,have always wondered about the pentagon our news reported aomething crazey then never again did i see it or see where it was corrected

Heather_118's picture

http://www.youtube.com/watch?v=BmP2Vy8K0i0
this describes the dimensions of a plane vs the hole in the pentagon

Heather_118's picture

http://www.youtube.com/watch?v=mcWT2lQszEE
CNN report right after the attack

Heather_118's picture

http://www.youtube.com/watch?v=8Vnu_yiUzls
this does not look like a boeing

Heather_118's picture
Heather_118's picture

Thanks Angel :) Lots to think about.

But.........I still don't buy anything FEMA reports, I delt alot with FEMA crap while in SAR and I learned to dislike them, alot!!!!.

TWO buildings falling exactly the same way, yet hit by two different planes, at two different times?
Did both planes have exactly the same amount of fuel and hit the buildings in JUST the right spot to mimic each others fall? My mind isn't wrapping itself around that.

Ok.....I can't remember what source I got this from, I'd have to do some digging, I believe it was from a movie made by family members of victims. Eyewitness reports of guards/employees/k9 handlers saying the bomb dogs were not allowed in the buildings for 2wks prior to 9/11 and that several sections of the towers were being closed/off limits for a month before 9/11.

Why would our gov't want to kill it's own people? Because it's profitable, that's why.

I've seen several videos of the 'plane' hitting the Pentagon, and it does not look like a plane, more like a missle, and aside from a casing that appeared to be a fuselage, there was no wreckage from the jetliner.

My thoughts origionally of the PA flight was that our planes shot it down and that is why there was hardly any wreckage and lack of hits with cadaver dogs................still don't know what to believe with that one ??????

I noticed the stuff you posted is from 2006, there has been alot more evidence unearthed since then. I have to wonder who paid Mr Tim Wilkenson to share his knowledge of the buildings with the public? I've also seen other reports of other Civil engineers who detest this type of information.

I'm pigheaded and when I believe in something, I really dig deep. It wasn't until a few years ago that I started asking questions after a local TV station was pirated by some truth seekers. I was also alerted by a good friend to start looking to the skies and to inquire about all the chemtrails we are seeing nowadays, this prompted me to do

kidrockangel's picture

Other Theories?

This section added 14 January 2006

This website generates many queries from people in response to some of the other theories that are put forward relating to the collapse - namely that it was a controlled explosion.

The initial impact/further weakening by fire reasoning is based on uncontestable knowledge about the behaviour of structures in general, and the weakening of steel under fire conditions, plus video footage of the events and examination of the steel afterwards. The official FEMA report written by engineering experts came to this conclusion based on the evidence.

However, should additional evidence come to light that supports a different theory, the author is willing to reassess his views.

The fire wasn't hot enough to melt the steel
There has never been a claim that the steel melted in the fire before the buildings collapsed, however the fire would have been very hot. Even though the steel didnt melt, the type of temperatures in the fire would have roughly halved its strength.

There would have been variations in the distribution of the temperature both in place in time. There are photos that show people in the areas opened up by the impact, so it obviously wasnt too hot when those photos were taken, but this is not to say that other parts of the building, further inside were not hotter. In addition, to make a reasonable conclusion from these photos, it would be important to know when they were taken. It might be possible that just after the impact the area wasnt very hot, but as the fire took hold the area got hotter.

The way the building collapsed must have been caused by explosions
One demolition expert on the day of the collapse said it looked like implosion but this is not very strong evidence. Implosion firstly requires a lot of explosives placed in strategic areas all around the building. When and how was this explosive placed in the building without anyone knowing about it. Second, implosion required more

kidrockangel's picture

Why Did It Collapse?

Tim Wilkinson, Lecturer in Civil Engineering

(This is an initial suggestion, originally written on Sept 11 2001 (with some minor subsequent changes) on one possible reason for failure, and should not be regarded as official advice.)
World Trade Center collapse

The structural integrity of the World Trade Center depends on the closely spaced columns around the perimeter. Lightweight steel trusses span between the central elevator core and the perimeter columns on each floor. These trusses support the concrete slab of each floor and tie the perimeter columns to the core, preventing the columns from buckling outwards.

After the initial plane impacts, it appeared to most observers that the structures had been severely damaged, but not necessarily fatally.

It appears likely that the impact of the plane crash destroyed a significant number of perimeter columns on several floors of the building, severely weakening the entire system. Initially this was not enough to cause collapse.

However, as fire raged in the upper floors, the heat would have been gradually affecting the behaviour of the remaining material. As the planes had only recently taken off, the fire would have been initially fuelled by large volumes of jet fuel, which then ignited any combustible material in the building. While the fire would not have been hot enough to melt any of the steel, the strength of the steel drops markedly with prolonged exposure to fire, while the elastic modulus of the steel reduces (stiffness drops), increasing deflections.
World Trade Center collapse

Modern structures are designed to resist fire for a specific length of time. Safety features such as fire retarding materials and sprinkler systems help to contain fires, help extinguish flames, or prevent steel from being exposed to excessively high temperatures. This gives occupants time to escape and allow fire fighters to extinguish blazes, before the building is catastrophically damag

Pages