Jets Impact the Twin Towers

The opening salvo in the escalating series of horrors on 9/11/01 was a jet smashing into the North Tower of the World Trade Center at 8:46 AM. The takeover of Flight 11 had occurred almost 30 minutes earlier, but it was the shocking impact with one of the famous Twin Towers that awakened the world to the unfolding attack. By 9:00 AM, television stations across the globe had gone live with the story of the disaster in Lower Manhattan. Thus many cameras were rolling when the South Tower was impacted by a second jet at 9:03 AM, producing brilliant fireballs.

Impacts and Fireballs

The jet that hit the North Tower flew in perpendicular to the tower's northeast face, and impacted around the center of the 95th floor, producing an impact gash that extended from the 92nd to the 98th floor. Most of the plane apparently lodged in the tower's core structure, the only piece of aircraft to emerge from the opposite side being a dense piece of landing gear. The burning jet fuel, atomized on impact, spilled out of the impact gash and through broken windows on the southeast side.

In contrast, the jet that hit the South Tower, 18 minutes later, veered to the right just before impact and hit the rightmost third of the tower's southwest wall, producing an impact gash that extended from the 78th to the 94th floor. The diagonal trajectory through the building allowed most of the plane to miss the tower's core structure, and much of its fuselage appeared to emerge from the east corner, while a great deal of the fuel escaped from the northeast and southwest walls. This produced huge fireballs that developed outside the building, in contrast with the greater containment of the fireballs in the North Tower impact.

Impact Damage

The jet impacts destroyed sections of perimeter wall columns on the faces of the towers they hit. Although the collisions left imprints that extended out to the wingtips of the jets, the ends of the wings destroyed only the aluminum cladding covering the perimeter columns, not the steel columns themselves. The South Tower's wall was damaged less than the North Tower's, since the columns at its impact zone were made of thicker steel.

According to FEMA's damage estimates, The North Tower impact destroyed from 31 to 36 of its perimeter columns, and the South Tower impact destroyed about 23 of its perimeter columns. Since each tower had 240 perimeter columns, the impacts destroyed only about 13 and 10 percent of the towers' perimeter columns, and only on a few floors.

The Jet Fuel

In the popular imagination, the jet fuel was the biggest factor in bringing down the towers. News reports emphasized that the transcontinental flights were fully loaded with fuel, while later government reports stated that the 767s were carrying about 10,000 of their 24,000-gallon capacity, and that most of the jet fuel likely burned off within five minutes. Thus, the jet fuel primarily served to ignite the post-crash fires rather than sustain them.