system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why was 911 decided to be the shorthand dial for emergency numbers? Why not other combinations that are easier to remember (e.g. 111, 123, etc.)?
gpt
Back in the day, we had rotary phones. Rather than pushing a button for each digit, you had to pull back the dial a certain amount based on what number you were dialing. (Hence where the term "dial" comes from.) On a rotary phone, 911 was a number that was both easy to dial, but also pretty much impossible to dial on accident.