That morning in 2001, 19 terrorists from the Islamist militant group AL-Qaeda hijacked four passenger jets, piloting two in the World Trade Center Towers, another into the Pentagon, while the fourth plane, crashed in Pennsylvania.
Nearly 3,000 people died in the attacks, including the 246 civilians and 19 hijackers aboard the four planes.
Here's how the deadly day unfolded.
At 8:46 a.m., five terrorist hijackers crashed American Airlines Flight 11 into the World Trade Center's North Tower.
Then at 9:03 a.m., another five hijackers crashed United Airlines Flight 175 into the South Tower.
Both towers collapsed within hours.
Almost every American adult alive today remembers where they were when this tragedy occurred.
The loss of 2,996 lives, including military personnel, and the police officers and fire fighters who went back into the towers to save people is memorialized every year now across the U.S on this day when America's resolve was truly tested like it never has before.
The attacks on September 11th are sometimes compared to the attack on Pearl Harbor.
Unfortunately, no peace treaty has been signed in this case, and the war on terror continues. And although steps have been taken in response, such as the killing of Osama Bin Laden, the mastermind behind the attacks. The resolve of America will continue to be tested, as long as there are those who have so little value of human life.
For NewsNight on the Patriot, I'm Brandon Evans.