September 11 attacks; 9/11
Refers specifically to the terrorist attacks on the United States on September 11, 2001. Used in news and historical contexts.
The September 11 attacks greatly changed American history.
He watched a documentary about the 9/11 attacks.
A broader term for simultaneous terrorist attacks; often used in Japanese media to describe the 9/11 attacks, but can refer to any coordinated terrorist incident.
Standard Japanese notation for the September 11 attacks, using Arabic numerals.
Kanji numeral spelling; less common but still seen in formal or vertical writing.
Compound of ９１１ (kyū-ichi-ichi, from the date September 11) and 事件 (jiken, 'incident'). A direct borrowing of the English '9/11' into Japanese date notation.