Það gerðist líka í New York fyrir mörgum árum að flugvél, töluvert smærri þó, skall í hlið Empire State byggingarinnar. Þetta olli vissulega miklum usla og brann ákveðinn hluti byggingarinnar mikið. En þó féll turninn ekki.

Ef ég man rétt, og þori ég ekki að leggja líf mitt að veði, þá kom þar fram að eftir rannsóknir fjölda vísindamanna og áralanga vinnu að turnarnir féllu vissulega, þrátt fyrir að það bryti öll eðlisfræðileg lögmál, en enga skýringu er hægt að gefa á því hvers vegna þeir féllu.

Þegar tvíburaturnarnir voru síðan á teikniborðinu einhverjum árum seinna þá mundi fólk eftir þessu enþá og var þá ákveðið að þar sem verið væri að ráðast í virkilega stóra framkvæmd, þá væri best að byggja turnana svo þeir ættu nú eftir að haldast uppi í nokkur ár. Þess vegna var ákveðið að nota alla helstu tækni þess tíma til þess að gera þá örugga fyrir því að boing 707 þota, stærsta þota þess tíma, gæti skollið á þeim án þess að þeir hryndu. Vissulega ekki af alveg sömu stærðargráðu og boing 757 (eða var það 747?) en ansi stór þota þrátt fyrir allt.

Despite shocks and explosions estimated to be equivalent to that of the 1995 truck bombing of the Alfred P. Murrah Federal Building in Oklahoma City (about 400 tons of TNT), the towers remained upright. “The buildings displayed a tremendous capacity to stand there despite the damage to a major portion of the gravity system, and for an hour or so they did stand there,” McNamara said. “The lateral truss systems redistributed the load when other critical members were lost. It's a testament to the system that they lasted so long.”

Newspapers and TV newscasts reported that the twin towers had been designed to withstand a collision with a Boeing 707. The events of September 11th show that this was indeed the case. “However, the World Trade Center was never designed for the massive explosions nor the intense jet fuel fires that came next—a key design omission,” stated Eduardo Kausel, another M.I.T. professor of civil and environmental engineering and panel member. The towers collapsed only after the kerosene fuel fire compromised the integrity of their structural tubes: One WTC lasted for 105 minutes, whereas Two WTC remained standing for 47 minutes. “It was designed for the type of fire you'd expect in an office building—paper, desks, drapes,” McNamara said. The aviation fuel fires that broke out burned at a much hotter temperature than the typical contents of an office. “At about 800 degrees Fahrenheit structural steel starts to lose its strength; at 1,500 degrees F, all bets are off as steel members become significantly weakened,” he explained.

When New York City's giant World Trade Center towers plunged to earth following successive suicide terrorist attacks on September 11th, the world was confronted with one of most shocking—and sickening—sights of modern times. The mechanisms by which these huge and seemingly solid edifices suddenly collapsed, snuffing out the lives of thousands, was the subject of a preliminary postmortem conducted last week in Cambridge, Mass. A panel of Boston area-based civil and structural engineers convened to discuss the fate of the superskyscrapers, struck by hijacked passenger planes, in front of an overflow audience on the campus of the Massachusetts Institute of Technology. Their starkly sobering analyses highlighted the vulnerabilities of ultra-tall buildings to fire and pointed out steps that could be taken to lessen them.

After first describing the highly redundant structural system that kept the 110-story twin towers standing for decades despite hurricane-force winds and a terrorist truck bomb, the engineers then delineated how that system was breached and finally overcome on that fateful day when America was attacked. The main culprits in bringing the famously lofty buildings down, they concluded, were the two intensely hot infernos that erupted when tens of thousands of gallons of aviation fuel spilled from the doomed airliners. Once high temperatures weakened the towers' supporting steel structures, it was only a matter of time until the mass of the stories above initiated a rapid-sequence “pancaking” phenomena in which floor after floor was instantly crushed and then sent into near free fall to the ground below. Significantly, the panel stated that any mitigating reinforcements and redundancies added to these buildings could have only delayed the inevitable failure, though they would have bought more time for the evacuation of the occupants. No existing or foreseeable economically viable skyscraper structure, they agreed, could have withstood this kind of cruel onslaught. Clearly, prevention is the best defense against this kind of assault.

Ein fór á Pentagon og skildi ekkert brak eftir sig og örlítið títuprónshaus gat á vegg byggingarinnar þar sem enginn var blessanalega að vinna á þeim tíma

Kæri félagi, ég skil vel að þú viljir halda í barnadrauminn um það að allt sé eins svart og hvítt í heiminum eins og hann lítur út fyrir að vera, allt svo eins og valdamenn í heiminum láta hann líta út fyrir að vera.