The Twin Towers of the World Trade Center fell on September 11, 2001, following terrorist attacks. The South Tower collapsed at 9:59 a.m., 56 minutes after being struck by United Airlines Flight 175. The North Tower collapsed later, at 10:28 a.m., about one hour and 42 minutes after being hit by American Airlines Flight 11 at 8:46 a.m. Both buildings burned and progressively collapsed due to the intense fires caused by the impacts of the airplanes. These events resulted in the complete destruction of both towers within less than two hours on that day.
