Only a few minutes after the first plane, American Airlines Flight 11, crashed into the North Tower of the World Trade Center at 8:46 a.m., causing massive destruction and trapping hundreds above the impact zone, the second plane, United Airlines Flight 175, struck the South Tower at 9:03 a.m. This second impact was captured live on television, shocking millions of viewers and confirming that the crashes were deliberate terrorist attacks

. Immediately following the first crash, emergency evacuations began in both towers, though escape from the upper floors of the North Tower was impossible due to the plane severing all stairwells in the impact zone. Smoke and fire spread rapidly, and many people trapped above the crash site in the North Tower were forced to jump to escape the flames

. Air traffic controllers and military defense sectors were alerted to the hijacking and crash shortly after the first impact, mobilizing the Air National Guard to respond. However, the attacks continued with the second plane hitting the South Tower less than 20 minutes later

. In summary, within minutes after the first plane hit the North Tower, the second plane crashed into the South Tower, triggering mass evacuations, widespread panic, and the realization that the United States was under coordinated terrorist attack