The day of September 11, 2001, or 9/11 as it is referred to, and what happened on this day changed America and the world as we know it.

Four commercial airliners were hijacked by al-Qaeda — two flew into the North and South towers of the World Trade Centres respectively, the third flew into the Pentagon, US' military headquarters, and the fourth, intended to crash into the White House or the Capitol Building, missed its target. al-Qaeda leader Osama bin Laden first denied and then, in 2014, accepted responsibility for the hideous attack. But it was only after a decade that he was found in Pakistan and shot dead during Operation Neptune Spear.

There were over 2,977 fatalities, the market fell, the economy was down, several jobs were lost and a nation and its people were in pain. In the aftermath, that is in 2018, over 10,000 people were diagnosed with 9/11 related cancer because several toxic fumes, dust and debris were released into the air after the attack.

This terrorist attack put many nations on their toes and the US really stepped up its efforts to counter future terrorist attacks and safeguard security like creating the Department of Homeland Security and National Commission on Terrorist Attacks Upon the United States.