9/11

9/11 was a terrorist attack conducted on september 11th, 2001, in which 3000 people died when the terrorists hijacked 2 planes and crashed into the world trade center (commonly refered to as the Twin Towers)

Allegedly orchestrated by Al Qaeda and Osama Bin Laden, who took the blame for it, however a lot of people blame domestic and external governments, commonly the USA itself or Israel.