3-1-1

The requirement for passengers to take their shoes off at TSA security checkpoints came nearly five years later due to “intelligence pointing to a continuing threat,” an official TSA history notes, following a foiled August 2006 terrorist plot to detonate liquid explosives onboard transatlantic flights. The TSA introduced its 3-1-1 liquids rule for carry-on luggage in response.

2025 July 8, Pete Muntean and Alexandra Skores, “TSA will no longer require all passengers to take shoes off at airport security checkpoints”, in CNN

9-1-1 is a phone number everyone knows growing up; its mention is associated with fear and disaster. If you’re dialing 9-1-1, something’s wrong. Using it in conjunction with another terrible event, then, isn’t a huge leap. If the events took place on March 11 (like the public information phone number 3-1-1), perhaps the metonym wouldn’t be “3/11,” since it isn’t similarly visceral. (It’s worth noting that the Madrid train bombings, which took place on March 11, are known in Spain as “11-M” due to the country’s use of the date-before-month method of date formatting.) (This connection between “9/11” and 9-1-1 is made evident in the story of its initial usage.

2015 January 16, Rick Paulas, “The Linguistics of Tragedy”, in Pacific Standard, archived from the original on 22 Apr 2025