Answer:
On September 11th, 2001, a terrorist attack was undertaken against the world trade center wherein aircraft were flown into both towers, resulting in a bifold collapse of the structures with many civilians still inside. This, added to the death toll of emergency responders in the wake of the collapse, awoke mass outcry.
The Bush administration responded by starting a "War on Terror" which rages on today, and security measures in transit regions like airports were massively increased in scope.
Step-by-step explanation: