Recently, Rosie O’Donnell, a co-host of ABC talk show The View, made comments on the show that renewed controversy over the collapse of World Trade Center 7.
While saying she didn’t know what to believe about the U.S. government’s involvement in the attacks of Sept. 11, she said, “I do believe that it’s the first time in history that fire has ever melted steel. I do believe that it defies physics that World Trade Center tower 7—building 7, which collapsed in on itself—it is impossible for a building to fall the way it fell without explosives being involved. World Trade Center 7. World Trade [Center] 1 and 2 got hit by planes—7, miraculously, the first time in history, steel was melted by fire. It is physically impossible.”
I'm sure lots of metallurgists will be interested to know their techniques for making steel, which depend on melting the stuff with fire, don't work.
For those interested in what physics and demolition experts have said regarding WTC 7’s collapse, as detailed in our book Debunking 9/11 Myths, Popular Mechanics offers these notes:
1. Initial reports from the Federal Emergency Management Agency (FEMA) misunderstood the amount of damage the 47-floor WTC7 sustained from the debris of the falling North Tower—because in early photographs, WTC7 was obscured by smoke and debris.
2. The North and South Towers of the World Trade Center weren’t knocked down by planes—they both stood for more than a half-hour after the impacts. But the crashes destroyed support columns and ignited infernos that ultimately weakened—not melted—the steel structures until the towers could no longer support their own weights (NIST offers a primer here). Ms. O’Donnell fundamentally misstates the case with her use of the word “melted”: Evidence currently points to WTC7 also collapsing because fires weakened its ravaged steel structure.
3. Demolition experts tell Popular Mechanics that wiring a building the size of WTC7 for clandestine demolition would present insurmountable logistical challenges. That issue aside, there’s a clear-cut engineering explanation for why the building fell the way it did. Trusses on the fifth and seventh floors of the building were designed to transfer loads from one set of columns to another; with the south face heavily damaged, the other columns were likely overtaxed. In engineering terms, the “progressive collapse” began on the eastern side, when weakened columns failed from the damage and fire. The entire building fell in on itself as the slumping east side dragged down the west side in a diagonal pattern. Still, damage to the Verizon Building (see p. 21 of this report), directly west of WTC7, and to Fiterman Hall (see here) directly north, show that it was hardly an orderly collapse.