9/11

Shorthand for September 11, 2001, when two planes hijacked by Al-Qaeda terrorists flew into the Twin Towers, causing them to collapse top-down onto the streets of New York. Another plane was flown into Pentagon building in Arlington, Virginia while a fourth, presumed to be targeting somewhere in Washington, DC, was deliberately crashed near Shanksville, Pennsylvania as its passengers fought to regain control from the terrorists. The death toll is currently at 2,996.

Widely considered by Americans to be the true start of the 2000s. then-US President George W. Bush was often jocularly connected to the attacks on sites such as 4chan ("Bush did 9/11").

The most common depiction of the event depicts smoke exiting either of the towers.