According to the official account, the Twin Towers were brought down by airplane impacts and fire, and in the case of WTC 7, by fire alone. One implication of this account is that the destruction would have produced no molten steel or molten iron (which is produced in a thermite reaction). Structural steel does not begin to melt until it reaches about 1,482°C (2,700°F), and iron does not melt until it reaches 1,538°C (2,800°F).  The fires ignited by the plane crashes, even with the help of jet fuel, could not have been hotter than 1,000°C (1,832°F), meaning that they would have been at least 1000 degrees F. cooler than what would be necessary to melt steel/iron. The presence of molten steel or iron, therefore, would have implied that the building steel had been melted by something other than the airplane impacts and the resulting fires.
The Official Account
There is no evidence that any molten steel or iron was found in any of the WTC buildings.
The NIST report showed that the Twin Towers were brought down by the airplane impacts and the resulting fires, which were ignited by jet fuel.  WTC 7, which was not hit by a plane, was brought down by fire alone.  There would, therefore, have been no reason for molten steel or iron to have been produced. 
Molten steel or iron was not mentioned in The 9/11 Commission Report,  the NIST report about the Twin Towers,  or the NIST report about WTC 7.  This silence about molten steel or iron implies its absence.
The existence of molten steel (or iron) was inexplicitly denied by one of the authors of the NIST reports, engineer John L. Gross.  At a lecture at the University of Texas in October 2006, Gross was asked a question about “a pool of molten steel,” to which he replied:
“Let’s go back to your basic premise that there was a pool of molten steel. I know of absolutely nobody — no eyewitnesses said so, nobody’s produced it.” 
In a post-report publication (September 2011), NIST wrote: “NIST investigators and experts from the American Society of Civil Engineers (ASCE) and the Structural Engineers Association of New York (SEONY) — who inspected the WTC steel at the WTC site and the salvage yards — found no evidence that would support the melting of steel in a jet-fuel ignited fire in the towers prior to collapse.”
Moreover, this report said:
“The condition of the steel in the wreckage of the WTC towers (i.e., whether it was in a molten state or not) was irrelevant to the investigation of the collapse since it does not provide any conclusive information on the condition of the steel when the WTC towers were standing.”
Finally, this report said:
“Under certain circumstances it is conceivable for some of the steel in the wreckage to have melted after the buildings collapsed. Any molten steel in the wreckage was more likely due to the high temperature resulting from long exposure to combustion within the pile than to short exposure to fires or explosions while the buildings were standing.” 
- The NIST reports attributed the collapses to jet fueled fires, which were not hot enough to produce molten steel or iron.
- There was no evidence for molten steel or iron, and there was no reason to expect it.
- Even if there had been molten steel or iron in the debris afterwards, it would have been irrelevant to the cause of the collapses.
The Best Evidence
Not one of those claims can be maintained:
- The evidence of molten steel or iron cannot be called “irrelevant,” given the fact that the building fires, as NIST pointed out, cannot explain it. The only explanation NIST suggested was that, if there was molten steel or iron, it would have been “due to the high temperature resulting from long exposure to combustion within the pile.” But NIST claimed that the buildings were brought down by building fires, which at most could have reached 1,000°C (1,832°F.) So the idea that burning debris from these buildings could have reached anywhere close to the temperature needed to melt structural steel (1,482°C, 2,700°F),  without the help of explosive or incendiary material, is implausible. It is also unscientific. Physicist Steven Jones has written: “Are there any examples of buildings toppled by fires or any reason other than deliberate demolition that show large pools of molten metal in the rubble? I have posed this question to numerous engineers and scientists, but so far no examples have emerged. Strange then that three buildings in Manhattan, supposedly brought down finally by fires, all show these large pools of molten metal in their basements post-collapse on 9-11-2001. It would be interesting if underground fires could somehow produce large pools of molten steel, for example, but then there should be historical examples of this effect since there have been many large fires in numerous buildings. It is not enough to argue hypothetically that fires could possibly cause all three pools of orange-hot molten metal.” The fact that the pools of metal had an orange color was crucial, Jones explained, because something had raised the temperature of iron to more than 2,000°C (3,632°F). 
- There were two types of evidence for molten steel or iron in the debris:
- Physical evidence, which was presented in a 2002 report by FEMA and elsewhere.
- Testimonial evidence from many credible witnesses, including firefighters and other professionals.
I. Physical Evidence
I-A. The 2002 FEMA Report
New York Times journalist James Glanz, writing near the end of 2001 about the collapse of WTC 7, reported that some engineers said that a “combination of an uncontrolled fire and the structural damage might have been able to bring the building down,” but that this “would not explain,” according to Dr. Barnett, “steel members in the debris pile that appear to have been partly evaporated in extraordinarily high temperatures.” 
Glanz was referring to Jonathan Barnett, a professor of fire protection engineering at the Worcester Polytechnic Institute (WPI). Early in 2002, Barnett and two WPI colleagues published an analysis of a section of steel from one of the Twin Towers, along with sections from WTC 7, as an appendix to FEMA’s 2002 World Trade Center Building Performance Study.  Their discoveries were also reported in a WPI article entitled “The ‘Deep Mystery’ of Melted Steel,” which said:
“[S]teel — which has a melting point of 2,800 degrees Fahrenheit [1538°C] — may weaken and bend, but does not melt during an ordinary office fire. Yet metallurgical studies on WTC steel brought back to WPI reveal that a novel phenomenon — called a eutectic reaction — occurred at the surface, causing intergranular melting capable of turning a solid steel girder into Swiss cheese.”
Stating that the New York Times called these findings “perhaps the deepest mystery uncovered in the investigation,” the article added:
“A one-inch column has been reduced to half-inch thickness. Its edges — which are curled like a paper scroll — have been thinned to almost razor sharpness. Gaping holes — some larger than a silver dollar — let light shine through a formerly solid steel flange. This Swiss cheese appearance shocked all of the fire-wise professors, who expected to see distortion and bending – but not holes.” 
In discussing “the deepest mystery,” the New York Times story said: “The steel apparently melted away, but no fire in any of the buildings was believed to be hot enough to melt steel outright.”  That was an understatement, because a building fire, even with a perfect mixture of air and fuel, could at most reach 1,000°C (1,832°F).  In fact, Professor Thomas Eagar of MIT estimated that the fires were “probably only about 1,200 or 1,300°F [648 or 704°C].” 
I-B. The RJ Lee Report
In May 2004, the RJ Lee Group issued a report, entitled “WTC Dust Signature,” at the request of the Deutsche Bank, in order to prove (to its insurance company) that the building was “pervasively contaminated with WTC Dust, unique to the WTC Event.”  The report listed five elements in this signature, one of which was: “Spherical iron and spherical or vesicular silicate particles that result from exposure to high temperature.”  This was the only statement about iron’s being modified by high temperature in this 2004 report.
However, RJ Lee had written an earlier report in 2003, entitled “WTC Dust Signature Report,” which contained much more about iron. It said: “Particles of materials that had been modified by exposure to high temperature, such as spherical particles of iron and silicates, are common in WTC Dust … but are not common in ‘normal’ interior office dust.”  This 2003 version of the report even pointed out that, whereas iron particles constitute only 0.04 percent of normal building dust, they constituted an enormous amount of the WTC dust: 5.87 percent (meaning that there was almost 150 times more iron in the dust than normal).  This earlier version also explicitly stated that iron and other metals were “melted during the WTC Event, producing spherical metallic particles.” 
In addition, whereas the 2004 report did not use the word “vaporize,” this earlier version spoke of temperatures “at which lead would have undergone vaporization.”  Accordingly, whereas the 2004 report referred to “high temperatures,” the earlier report indicated that the temperatures were not merely high but extremely high, because for lead to boil and hence vaporize, it must be heated to 1,749°C (3,180°F). 
I-C. The USGS Report
In 2005, the United States Geological Survey (USGS) published a report entitled “Particle Atlas of World Trade Center Dust,” which was intended to aid the “identification of WTC dust components.” Among the components, it reported, were “metal or metal oxides” (which could not be distinguished by the USGS’s methods). “The primary metal and metal-oxide phases in WTC dust,” the report said, “are Fe-rich [iron-rich] and Zn-rich [zinc-rich] particles.”  The report included a micrograph of an “iron-rich sphere.” 
These iron-rich spherical particles — or “spherules,” as they are sometimes called – could only come about if iron is melted and then “sprayed into the air so that surface tension draws the molten droplets into near-spherical shapes.” 
Accordingly, the USGS report mentioned (without explaining) the existence of particles in the dust that should not have been there, according to the NIST explanation of the collapses.
I-D. Report by the Steven Jones Group
NIST also ignored a third scientific report describing phenomena in the WTC dust that could have been produced only by extremely high temperatures. Entitled, in fact, “Extremely high temperatures during the World Trade Center destruction,” this report, written by Steven Jones and seven other scientists, pointed out the existence of particles in the dust that required even higher temperatures than those implied by the RJ Lee and USGS reports.
Jones and his colleagues performed tests using their own samples of WTC dust, which had been collected shortly after the destruction of the WTC — either very shortly afterwards or from the inside of nearby buildings (which means that the dust could not have been contaminated by clean-up operations at Ground Zero). They reported finding “an abundance of tiny solidified droplets roughly spherical in shape (spherules),” which were primarily “iron-rich … and silicates.” The iron-rich spherules would have required a temperature of 1,538°C (2,800°F). The silicates often contained aluminum, and aluminosilicate spherules, which were found in abundance in the dust, would have required a temperature of 1,450°C (2,652°F). 
Iron could not have arisen from the steel alone and should not have been found in the rubble. The iron, which needs to be accounted for, is a byproduct of the thermite reaction.
Still more remarkable, the Jones group reported, was a spherule found in the dust that was not mentioned in USGS’s “Particle Atlas,” and which was obtained only through an FOIA request, namely, “a molybdenum-rich spherule,” which had been observed and studied by the USGS team. This information is remarkable, because molybdenum (Mo) is “known for its extremely high melting point”: 2,623°C (4,753°F).  The presence of this molybdenum-rich spherules in the WTC dust was not mentioned by NIST, although it could have learned about it from the article by the Jones group or directly from the USGS.
II. Testimonial Evidence
II-A. Testimony from Firefighters:
- New York Fire Department Captain Philip Ruvolo said: “You’d get down below and you’d see molten steel, molten steel, running down the channel rails, like you’re in a foundry, like lava.” 
- Joe O’Toole, a Bronx firefighter who worked on the rescue and cleanup efforts, reported that one beam lifted from deep below the surface months later, in February 2002, “was dripping from the molten steel.” 
- New York firefighters recalled in the documentary film Collateral Damages, “heat so intense they encountered rivers of molten steel.” 
II-B. Testimony from Other Professionals:
- Leslie Robertson, a member of the engineering firm that designed the World Trade Center, said 21 days after the attack: “When we were down at the B1 level, one of the firefighters said, ‘I think you’d be interested in this,’ and they pulled up a big block of concrete and there was a, like a little river of steel, flowing.” 
- Ron Burger, a public health advisor at the National Center for Environmental Health who arrived at Ground Zero September 12, 2001, said: “Feeling the heat, seeing the molten steel, the layers upon layers of ash, like lava, it reminded me of Mt. St. Helen’s and the thousands who fled that disaster.” 
- In late fall 2001, Dr. Alison Geyh of the Johns Hopkins School of Public Health reported: “Fires are still actively burning and the smoke is very intense. In some pockets now being uncovered, they are finding molten steel.” 
- Joe Allbaugh, the Director of FEMA, said in an October 2001 interview on CBS: “It’s just too hot for rescuers to get into [some] areas. So we do not know yet what’s in those areas, other than very hot, molten material.” 
- Dr. Keith Eaton reported in Structural Engineer: “They showed us many fascinating slides … ranging from molten metal which was still red hot weeks after the event, to 4-inch thick steel plates sheared and bent in the disaster.”
- Don Carson, a hazardous materials expert from the National Operating Engineers Union, said six weeks after 9/11: “There are pieces of steel being pulled out from as far as six stories underground that are still cherry red.” 
II-C. Testimony from Other Credible Witnesses:
- Greg Fuchek, vice president of a company that supplied computer equipment used to identify human remains, reported that “sometimes when a worker would pull a steel beam from the wreckage, the end of the beam would be dripping molten steel.” 
- Sarah Atlas, of New Jersey’s Task Force One Urban Search and Rescue, arrived at Ground Zero on September 11 and reported that “fires burned and molten steel flowed in the pile of ruins still settling beneath her feet.” 
- Tom Arterburn, writing in Waste Age, reported that the New York Department of Sanitation removed “everything from molten steel beams to human remains.” 
Rebuttal of Official Claims: Summary
- The claim that no evidence of any molten steel or iron was found in any of the WTC buildings is strongly refuted by three scientific reports, one from a government agency (USGS).
- John Gross’s claim that “no eyewitnesses said” that there was molten steel (or iron) was strongly and repeatedly contradicted.
- The claim that molten steel or iron would be irrelevant because it could have been produced in the combustion pile: This would mean claiming, with no scientific evidence and no plausibility, that combustion in an oxygen-starved pile of rubbish could have heated steel to at least 1500°C (2800°F).
- With regard to the NIST claim that molten steel or iron is “irrelevant to the investigation of the collapse” because “it does not provide any conclusive information on the condition of the steel when the WTC towers [including WTC 7] were standing”: Given the fact that the molten steel or iron in the debris could not have been produced without incendiaries or explosives, the presence of either of them indicates that some of the steel was melted before, or during, the final moments of the collapses.
- With regard to NIST’s statement in its post-report publication that there was no evidence for “the melting of steel in a jet-fuel ignited fire in the towers”: This is a statement that is truly irrelevant. The whole point is that the presence of melted steel and/or iron is an indication that the buildings must have been brought down by something other than fire.
None of the official claims about the non-existence of molten iron or steel in the destroyed WTC buildings withstand scrutiny. The fact that the rubble contained steel or iron that had been melted shows that the buildings were destroyed by something other than fire and airplane impact. Especially dramatic evidence of various types was provided by several facts: that the original RJ Lee report showed that there was almost 150 times more iron in the dust than normal; that the rubble contained steel with gaping holes, manifesting a “Swiss cheese appearance” that shocked the three “fire-wise professors” from Worcester Polytechnic Institute; that lead had been vaporized; that molybdenum had been melted; and that the metal pools contained iron that had been heated, as shown by the orange color, above 2,000°C (3,632°F).
When all of this physical evidence is combined with the testimony about explosions from many types of professionals, the claim that the Twin Towers were brought down by nothing other than the airplane impacts and resulting fires is simply not credible.
References for Twin Towers Point 6
- On iron, see “Iron” in WebElements: The Periodic Table on the Web. Steel, as an alloy of iron, comes in different grades, with a range of melting points, depending on the percent of carbon (which lowers the melting point), from 1,371°C (2,500°F) to 1,482°C (2,700°F); see “Alloys: Melting Point Chart”.
- NIST NCSTAR 1, Final Report on the Collapse of the World Trade Center Towers (archive copy), September 2005, p. 15. Regarding airplane impacts, see pp. 150-51; Jet fuel, pp. 24, 42; Fires, pp. 91, 127, 183
- NIST NCSTAR 1A, Final Report on the Collapse of World Trade Center Building 7 (archive copy), November 2008, xxxv. In NIST’s words, the collapse of WTC 7 was “the first known instance of the total collapse of a tall building primarily due to fires.”
- In a post-report publication (September 2011), NIST wrote: “In no instance did NIST report that steel in the WTC towers melted due to the fires. The melting point of steel is about 1,500 degrees Celsius (2,800 degrees Fahrenheit). Normal building fires and hydrocarbon (e.g., jet fuel) fires generate temperatures up to about 1,100 degrees Celsius (2,000 degrees Fahrenheit). NIST reported maximum upper layer air temperatures of about 1,000 degrees Celsius (1,800 degrees Fahrenheit) in the WTC towers [for example, see NCSTAR 1, Figure 6-36]” (archive copy). NIST Engineering Laboratory, “Questions and Answers about the NIST WTC Towers Investigation (Question 15),” September 19, 2011.
- The 9/11 Commission Report, 2004.
- NIST NCSTAR 1-9, Structural Fire Response and Probable Collapse Sequence of World Trade Center Building 7 (archive copy), Vol. 1, Chapter 8.
- NIST NCSTAR 1A, Final Report on the Collapse of World Trade Center Building 7, Federal Building and Fire Safety Investigation of the World Trade Center Disaster (archive copy), November 20, 2008.
- Dr. Gross was the Co-Project leader on Structural Fire Response and Collapse Analysis. See “John L. Gross”.
- October 18, 2006 lecture, University of Texas at Austin, on the collapse of the Twin Towers, “Dr. John Gross, N.I.S.T.” Date confirmed here.
- NIST Engineering Laboratory, “Questions and Answers about the NIST WTC Towers Investigation,” (Question 23) September 19, 2011.
- “Iron,” WebElements: The Periodic Table on the Web.
- Steven E. Jones, “Why Indeed Did the World Trade Center Buildings Completely Collapse?” Journal of 9/11 Studies, Vol. 3: September 2006, p. 18.
- James Glanz, “Engineers Suspect Diesel Fuel in Collapse of 7 World Trade Center,” New York Times, November 29, 2001.
- Jonathan Barnett, Ronald R. Biederman, and Richard D. Sisson, Jr., “Limited Metallurgical Examination,” FEMA, World Trade Center Building Performance Study, May 2002, Appendix C.
- Joan Killough-Miller, “The ‘Deep Mystery’ of Melted Steel,” WPI Transformations, Spring 2002.
- James Glanz and Eric Lipton, “A Search for Clues in Towers’ Collapse,” New York Times, February 2, 2002.
- Thomas Eagar and Christopher Musso, “Why Did the World Trade Center Collapse? Science, Engineering, and Speculation,” JOM: Journal of the Minerals, Metals & Materials Society 53/12 (2001), 8-11.
- Thomas Eagar, “The Collapse: An Engineer’s Perspective,” which is part of “Why the Towers Fell,” NOVA, April 30, 2002.
- RJ Lee Group, “Expert Report: WTC Dust Signature,” May 2004, 5.
- Ibid., 11.
- RJ Lee Group, “WTC Dust Signature Report: Composition and Morphology,” December 2003, 5.
- Ibid., 24.
- Ibid., 17.
- Ibid., 21.
- WebElements: “The Periodic Table on the Web.”
- Heather A. Lowers and Gregory P. Meeker, U.S. Geological Survey, U.S. Department of the Interior, “Particle Atlas of World Trade Center Dust,” 2005.
- To see enlarged photos of the iron-rich particles, go here, then click on “Yes” at the far right of the lines for “Iron-03” and “Iron-04.”
- Steven E. Jones et al., “Extremely high temperatures during the World Trade Center destruction,” Journal of 9/11 Studies, January 2008, 8.
- Ibid., 1-2.
- Ibid., 4. On its characteristics, see “Molybdenum” in WebElements: The Periodic Table on the Web.
- “Firefighter Describes Molten Metal at Ground Zero, Like a Foundry,” YouTube: TruthRadiator
- Jennifer Lin, “Recovery Worker Reflects on Months Spent at Ground Zero,” Knight Ridder, May 29, 2002.
- “Unflinching Look Among the Ruins,” New York Post, March 3, 2004. Part 1 of 5 (backup) of Étienne Sauret’s “Collateral Damages” (2003) was also available.
- “Les Robertson Confirms Molten Metal in WTC Basement,” (YouTube: IC911STUDIES) in a presentation at Stanford University. See also National Conference of Structural Engineers, October 5, 2001. (James M. Williams, SEAU President, “WTC: A Structural Success,” SEAU NEWS, The Newsletter of the Structural Engineers Association of Utah, October 2001, 3.
- Quoted in Francesca Lyman, “Messages in the Dust: What Are the Lessons of the Environmental Health Response to the Terrorist Attacks of September 11?” National Environmental Health Association, September 2003. (Editor’s Note: Also quoted in “The scene at Ground Zero.”)
- “Mobilizing Public Health,” Johns Hopkins Public Health, Late Fall, 2001.
- FEMA Director Allbaugh with Bryant Gumbel, CBS Early Show, October 4, 2001.
- Greg Gittrich, “FIRE MAY SMOLDER FOR MONTHS,” New York Daily News, November 1, 2001: 10 (pay-per-view)(backup of “FREE Article Preview”).
- Trudy Walsh, “Handheld APP Eased Recovery Tasks,” Government Computer News 21, no. 27a, 11 September 2002.
- “K-9/11: Tracking the Rescuers’ Trauma,” PENN Arts & Sciences, Summer 2002.
- Tom Arterburn, “D-Day: NY Sanitation Workers’ Challenge of a Lifetime,” Waste Age, 1 April 2002.