Fire, Not Explosives, Felled 3rd Tower on 9/11, Report Says

Fire, Not Explosives, Felled 3rd Tower on 9/11, Report Says

By ERIC LIPTON
Published: August 21, 2008

GAITHERSBURG, Md. — Fires in the 47-story office tower at the edge of the World Trade Center site undermined floor beams and a critical structural column, federal investigators concluded on Thursday, as they attempted to curb still-rampant speculation that explosives caused the building’s collapse on Sept. 11, 2001.

No one died when the tower, 7 World Trade Center, tumbled, as the estimated 4,000 office workers there at the time had evacuated before it gave way, nearly seven hours after the second of the twin towers came down.

But the collapse of 7 World Trade Center — home at the time to branch offices of the Central Intelligence Agency, the Secret Service and the Giuliani administration’s emergency operations center — is cited in hundreds of Web sites and books as perhaps the most compelling evidence that an insider secretly planted explosives, intentionally destroying the tower.

A separate, preliminary report issued in 2002 by the Federal Emergency Management Agency questioned whether diesel fuel tanks installed in the tower to supply backup generators — including one that powered the Giuliani administration’s emergency “bunker” — might have been to blame.

But S. Shyam Sunder, the lead investigator from the National Institute of Standards and Technology, based here in the suburbs of Washington, also rejected that theory on Thursday, even as he acknowledged that the collapse had been something of a puzzle.

“Our take-home message today is the reason for the collapse of World Trade Center 7 is no longer a mystery,” Dr. Sunder said at a news conference at the institute’s headquarters. “It did not collapse from explosives or fuel oil fires.”

The institute’s findings were released on Thursday as part of a 915-page report resulting from the work of more than 50 federal investigators and a dozen contractors over three years.

Conspiracy theorists have pointed to the fact that the building fell straight down, instead of tumbling, as proof that explosives were used to topple it, as well as to bring down the twin towers. Sixteen percent of the respondents in a Scripps Howard/Ohio University poll said it was very likely or somewhat likely that explosives were planted.

During the last four decades, other towers in New York, Philadelphia and Los Angeles have remained standing through catastrophic blazes that burned out of control for hours because of malfunctioning or nonexistent sprinkler systems. But 7 World Trade Center, which was not struck by a plane, is the first skyscraper in modern times to collapse primarily as a result of a fire. Adding to the suspicion is the fact that in the rush to clean up the site, almost all of the steel remains of the tower were disposed of, leaving investigators in later years with little forensic evidence.


Using videos, photographs and building design documents, the investigators at the National Institute spent the last three years building an elaborate computer model of 7 World Trade Center that they used to test various chains of events to figure out what caused the collapse, Dr. Sunder said.

The investigators determined that debris from the falling twin towers damaged structural columns and ignited fires on at least 10 floors at 7 World Trade Center, which stood about 400 feet north of the twin towers. But the structural damage from the falling debris was not significant enough to threaten the tower’s stability, Dr. Sunder said.

The fires on six of the lower floors burned with particular intensity because the water supply for the sprinkler system had been cut off — the upper floors had a backup water supply — and the Fire Department, devastated by the collapse of the twin towers, stopped trying to fight the blaze.

Normally, fireproofing on a skyscraper should have been sufficient to allow such a blaze to burn itself out and leave the building damaged but still standing. But investigators determined that the heat from the fire caused girders in the steel floor of 7 World Trade Center to expand. As a result, steel beams underneath the floors that provided lateral support for the tower’s structural columns began to buckle or put pressure against the vertical structural columns.

These fires might have been fed partly by the diesel from tanks and a pressurized fuel line, which were on the fifth to the ninth floors, Dr. Sunder said. But the analysis showed that even in the worst case, the diesel fuel-fed fire would not have burned hot enough or long enough to have played a major role in weakening the structure. The investigators determined that the fire that day was fed mainly by office paper and furnishings.

The collapse started when a girder on the 13th floor disconnected from a critical column — listed as Column 79 — that supported a long open floor span, the report said. Once that floor gave way, the floors below it down to the fifth floor also collapsed, although this was not visible from the building’s exterior.

Without lateral support for nine stories, Column 79 buckled, and the floors above gave way all the way up to the roof. Only then did the collapse become visible from the exterior with a penthouse area on the roof first falling in, followed by what looked like the sudden implosion of the tower, Dr. Sunder said. “The physics is consistent, it is sound, it has been analyzed,” he said.

Skeptics have questioned whether explosives were planted at the three towers at ground zero, and at the Pentagon as well, often contending that the Bush administration had planned the catastrophes to provide a justification to invade Iraq and Afghanistan. What started as a small number of such conspiracy theorists ballooned into a movement of sorts, largely fed by Internet sites and homemade videos.

Dr. Sunder said the investigators considered the possibility that explosives were used, but ruled it out because the noise associated with such an explosion would have been 10 times louder than being in front of the speakers at a rock concert, he said, and detectable from as far as a half a mile away. He said that interviews with eyewitnesses and a review of video taken that day provided no evidence of a sound that loud just before the collapse.

The skeptics — including several who attended Thursday’s news conference — were unimpressed. They have long argued that an incendiary material called thermite, made of aluminum powder and a metal oxide, was used to take down the trade center towers, an approach that would not necessarily result in an explosive boom. They also have argued that a sulfur residue found at the World Trade Center site is evidence of an inside job.

Dr. Sunder said the investigators chose not to use the computer model to evaluate whether a thermite-fueled fire might have brought down the tower, since 100 pounds of it would have had to have been stacked directly against the critical column that gave way, which he said they did not believe had occurred.

To the skeptics, it was a glaring omission.

“It is very difficult to find what you are not looking for,” said Shane Geiger, who contributes to a Web site that follows the topic and who had come to Maryland from Texas to quiz Dr. Sunder about his findings, with a bumper sticker on his laptop computer that says, “9-11 was an inside job.”

Dr. Sunder attempted to patiently answer the questions that Mr. Geiger and another obvious critic presented to him during the news conference. Five armed police officers and a bomb-sniffing dog stood guard near the rear of the room.

Dr. Sunder said there were no apparent flaws in 7 World Trade Center’s design that contributed to its collapse and that it met New York City codes. But there are some important lessons for other skyscrapers, he said, as engineers and architects should consider how the heat from fires can weaken structural elements, potentially causing a so-called progressive collapse.

Owners of tall buildings with a similar floor design — he could not estimate how many such towers exist in the United States — should immediately consider whether to install reinforcements, he said, and perhaps codes should be changed to address the weakness.

A new, substantially different 7 World Trade Center — now 52 stories — reopened at roughly the same site in 2006. The new building has extra safety features, including wider emergency stairwells and a fire-resistant refuge area on each floor.

Within moments after the news conference ended, leaders of a group called Architects and Engineers for 9/11 Truth held their own telephone conference briefing, dismissing the investigation as flawed.

“How much longer do we have to endure the coverup of how Building 7 was destroyed?” said Richard Gage, a California architect and leader of the group.


Told of the doubts, Dr. Sunder said he could not explain why the skepticism would not die.

“I am really not a psychologist,” he said. “Our job was to come up with the best science.”

http://www.nytimes.com/2008/08/22/n...&bl&ei=5087&en=920506ca2f959545&ex=1219464000

 

Debunking NIST's conclusions about WTC 7 is as easy as shooting fish in a barrel.


Symmetrical Collapse

NIST lamely tried to explain the symmetrically collapse as follows:

WTC 7’s collapse, viewed from the exterior (most videos were taken from the north), did appear to fall almost uniformly as a single unit. This occurred because the interior failures that took place did not cause the exterior framing to fail until the final stages of the building collapse. The interior floor framing and columns collapsed downward and pulled away from the exterior frame. There were clues that internal damage was taking place, prior to the downward movement of the exterior frame, such as when the east penthouse fell downward into the building and windows broke out on the north face at the ends of the building core. The symmetric appearance of the downward fall of the WTC 7 was primarily due to the greater stiffness and strength of its exterior frame relative to the interior framing.

NIST can't have it both ways. If the exterior frame was so stiff and strong, then it should have stopped the collapse, or - at the very least - we would have seen a bowing effect where tremendous opposing forces were battling each other for dominance in determining the direction of the fall.

In real life, the thick structural beams and "stiff [and strong]" exterior frame used in the building should have quickly stopped any partial collapse, unless the support columns were all blown. At the very worst, we should see a 1 or 2 floor partial collapse.


Freefall Speed

NIST said that WTC 7 fell at 40% slower than freefall speed. But it collapsed alot faster than it would have if the structural supports were not all blown away at the same instant. 40% slower isn't very impressive -- that's like arguing that a rock falling through concrete 40% slower than a rock falling through the air is perfectly normal.

Again, why did the building collapse at all, given that the thick structural beams should have quickly stopped any partial collapse?

Fires Knocked Down Steel-Frame Buildings

NIST said fires alone brought down Building 7, but other office fires have burned longer and hotter without causing collapse.

No Explosive Sounds

NIST also said:

"No blast sounds were heard on the audio tracks of video recordings during the collapse of WTC 7 or reported by witnesses."

Oh, really?

What about , this
, this, this , this, this , this, and this?

Moreover, as discussed below, high-tech explosives don't necessarily make the same loud "booms" that dynamite make.

High-Tech Explosive Residues

And why were there residues for high-tech explosives at ground zero (and see this) ?

Molten and Partially Evaporated Steel

And what about the pools of molten metal at ground zero for months ? And why was the at and under the ground at the site of WTC 7 as hot as the ground under WTC 1 and 2?

And the New York Times wrote that partly EVAPORATED steel beams were found at WTC 7 . But normal office and diesel fires are not NEARLY hot enough to evaporate steel. Hydrocarbon fires fueled by diesel (which was apparently stored at WTC 7) and normal office materials cannot evaporate steel. Steel does not evaporate unless it is heated to at least 5,000 degrees Fahrenheit . Everyone agrees that fires from conventional building fires are thousands of degrees cooler than that.

Pre-Knowledge

And why didn't NIST address the obvious pre-knowledge by everyone around and well in advance that 7 was going to come down?

Experts

And why didn't NIST address what these experts say?:

* The former head of the Fire Science Division of the government agency which claims that the World Trade Centers collapsed due to fire (the National Institute of Standards and Technology), who is one of the world’s leading fire science researchers and safety engineers, a Ph.D. in mechanical engineering (Dr. James Quintiere), called for an independent review of the World Trade Center Twin Tower collapse investigation. "I wish that there would be a peer review of this," he said, referring to the NIST investigation. "I think all the records that NIST has assembled should be archived. I would really like to see someone else take a look at what they've done; both structurally and from a fire point of view. ... I think the official conclusion that NIST arrived at is questionable.

* Two professors of structural engineering at a prestigious Swiss university (Dr. Joerg Schneider and Dr. Hugo Bachmann) said that, on 9/11, World Trade Center 7 was brought down by controlled demolition

* Kamal S. Obeid, structural engineer, with a masters degree in Engineering from UC Berkeley, of Fremont, California, says:

"Photos of the steel, evidence about how the buildings collapsed, the unexplainable collapse of WTC 7, evidence of thermite in the debris as well as several other red flags, are quite troubling indications of well planned and controlled demolition"

* Ronald H. Brookman, structural engineer, with a masters degree in Engineering from UC Davis, of Novato California, writes:

"Why would all 47 stories of WTC 7 fall straight down to the ground in about seven seconds... ? It was not struck by any aircraft or engulfed in any fire. An independent investigation is justified for all three collapses including the surviving steel samples and the composition of the dust."

* Graham John Inman, structural engineer, of London, England, points out :

"WTC 7 Building could not have collapsed as a result of internal fire and external debris. NO plane hit this building. This is the only case of a steel frame building collapsing through fire in the world. The fire on this building was small & localized therefore what is the cause?"

* A Dutch demolition expert (Danny Jowenko) stated that WTC 7 was imploded

* A prominent physicist with 33 years of service for the Naval Research Laboratory in Washington, DC (Dr. David L. Griscom) said that the official theory for why the Twin Towers and world trade center building 7 collapsed "does not match the available facts" and supports the theory that the buildings were brought down by controlled demolition


http://georgewashington2.blogspot.com/2008/08/debunking-nists-conclusions-about-wtc-7.html

Ops !

 

Oh !! too bad they are getting bigger every single day

www.ae911truth.org