Terrifying History on Instagram: "On September 11, 2001, at 9:03 a.m., United Airlines Flight 175 struck the South Tower of the World Trade Center. The impact was broadcast live on television, confirming to millions of viewers that the earlier crash into the North Tower was not an isolated accident but part of a coordinated terrorist attack on the United States. The Boeing 767 hit the South Tower between the 78th and 84th floors at a speed of approximately 590 miles per hour. The collision insta