September 11, 2001, at 8:45 a.m. on a clear Tuesday morning, was the deadliest day in history for New York City firefighters: 343 were killed, and a total of 2,996 person's list their lives. 

An American Airlines Boeing 767 loaded with 20,000 gallons of jet fuel crashed into the north tower of the World Trade Center in New York City.
The attackers were Islamic terrorists from Saudi Arabia and several other Arab nations. Reportedly financed by the al-Qaeda terrorist organization of Saudi fugitive Osama bin Laden, they were allegedly acting in retaliation for America’s support of Israel , its involvement in the Persian Gulf War and its continued military presence in the Middle East.

On September 11, 2001, 19 militants associated with the Islamic extremist group al-Qaeda hijacked four airplanes and carried out suicide attacks against targets in the United States. Two of the planes were flown into the twin towers of the World Trade Center in New York City, a third plane hit the Pentagon just outside Washington, D.C., and the fourth plane crashed in a field in Pennsylvania. Almost 3,000 people were killed during the 9/11 terrorist attacks, which triggered major U.S. initiatives to combat terrorism and defined the presidency of George W. Bush.
​At 10:30 a.m., the north building of the twin towers collapsed. Only six people in the World Trade Center towers at the time of their collapse survived. Almost 10,000 others were treated for injuries, many severe.
Meanwhile...
https://asehappen.com/2017/09/11/shocking-stories-from-911-attack-in-america-and-list-of-victims/

I Remember that day like yesterday.

An aunt had this close call with death on that day. I thank God for her life.
It was a horrible experience.

this event shook the world and caught everyone by suprise,its been long since it happened