The September 11th attacks consisted of four passenger plane hijackings conducted by the terrorist group al-Qaeda. All four planets crashed, killing all passengers and hijackers aboard, yet one plane did not make it to its "desired destination."
In response to the September 11th attacks, president Bush started the "war on terror." This resulted in the war in Afghanistan, the United States' longest war.
The war lasted over 13 years and resulting in 26,270 civilian deaths and over 27,000 military deaths.
2,977 deaths: The number of victims of the 9/11 attacks.
6,000+ people were non-fatally injured.
Furthermore, the attacks resulted in over three trillion dollars worth of damage to infrastructure, property, and various other important items.
The war in Afghanistan cost over 450 billion dollars.