AT 9:03:11 A.M., less than seventeen minutes after American Flight 11 devastated the North Tower, United Flight 175 bored deep into the South Tower.
The plane struck the tower’s south face, twenty-three feet from the midpoint, toward the southeast corner. The off-center jolt caused the upper floors to rotate like a boxer’s torso twisted from an unexpected blow. The entire building vibrated from rooftop to ground. The plane struck on a 38-degree angle, its right wing sharply higher than its left. The nose, pointed slightly downward, hit the slab of the 81st floor, near where Stan Praimnath trembled under his desk. The immediate impact lasted about six-tenths of a second.
Just as parts of American Flight 11 tore through the North Tower, the right engine of Flight 175 passed entirely through the South Tower and blew through the building’s northeast corner. It damaged the roof of a neighboring building before landing fifteen hundred feet north of the tower, near the corner of Murray and Church Streets. The right landing gear followed a similar trajectory.
Damage from the fuselage and the 156-foot wingspan stretched across nine floors, from the 77th to 85th floors. The two additional impact floors, compared to Flight 11’s damage, resulted from the more banked approach. The impact shattered 433 windows on the south, west, and east facades. It cut the pipes for fire sprinklers. It destroyed nearly all elevator service, severing cables and trapping occupants, although one freight car from the lobby to the fortieth floor remained operable.
Mitchell Zuckoff describing the horror inflicted on the South Tower of the World Trade Centre on September 11, 2001. Fall and Rise: the Story of 9/11, Chapter 14, pp 275-276.