From the Wikipedia article: >As it happens, the choice of 999 was fortunate for accessibility reasons, compared with e.g. lower numbers, because in the dark or

From the Wikipedia article: >As it happens, the choice of 999 was fortunate for accessibility reasons, compared with e.g. lower numbers, because in the dark or in dense smoke 999 could be dialled by placing a finger one hole away from the dial stop (see the articles on rotary dial and GPO telephones) and rotating the dial to the full extent three times. This enables all users including the visually impaired to easily dial the emergency number. It is also the case that it is relatively easy for 111, and other low-number sequences, to be called accidentally, including when transmission wires making momentary contact produce a pulse similar to dialling (e.g. when overhead cables touch in high winds) So maybe by fortune only, but it doesn't sound so crappy. On the other hand, anecdotally (we have had 112 or 113 here for as long as I can remember) I have seen reports on newspapers of people (with movenments limited, like being tied or wounded or however impaired) that managed to "dial" these "low" numbers by just quickly pushing and releasing the hook button with their foot (or nose, etc.).