Four planes were hijacked and carried out suicide attacks by 19 Al-Qaeda members on September 11, 2001.
First plane crashed into the north tower of the World Trade Center in NY City at 8:45 a.m.
18 minutes later, the second plane sliced into the south tower near the 60th floor that led to the structural collapse of the giant concrete building.
At 9:45 a.m. the third plane hit Pentagon just outside Washington, D.C.
Jet fuel from the 3rd plane caused a devastating inferno.
The fourth plane was hijacked about 40 minutes after leaving Newark International Airport in New Jersey.
The passengers fought the four hijackers and are suspected to have attacked the cockpit with a fire extinguisher.
The plane sped toward the ground and crashed in a rural field in western Pennsylvania at 10:10 a.m.
2,996 people were killed and more than 6,000 others wounded.
At 7 p.m., President George W. Bush addressed the whole nation from his Oval office and held Al-Qaeda responsible for the attack.
United States declared war on terror and led an military effort to destroy the Taliban regime in Afghanistan began on October 7, 2001.
Within two months, U.S forces had effectively removed Taliban from operational power.
Osama Bin Laden, the mastermind behind the 9/11 attacks, remained at large until May 2, 2011.
He was finally tracked down and killed by U.S Navy Seals at a hideout in Abbottabad, Pakistan in June 2011, after 10 years of 9-11 tragedy.
President Barack Obama later announced the beginning of large-scale troop withdrawals from Afghanistan.