On September 11, 2001, members of the Islamic extremist group Al Qaeda coordinated four attacks using hijacked commercial airliners in the United States.
Two iconic towers fell. The Pentagon sustained major damage. Nearly 3,000 victims lost their lives. Countless more suffered immediate injuries and long-term health issues that are still being felt to this day.
The 9/11 attacks changed America, and the world, forever.
Here's what it looked like on the ground, from the streets of New York to the Pentagon to a field outside of a Pennsylvania town, from the point of view of people who were there.
The first attack:
The first tower was struck at 8:46 a.m. on September 11, 2001.
Five attackers, armed with box cutters, crashed American Airlines Flight 11 into the north face of the north tower of the World Trade Center complex in lower Manhattan.