The wire is highly unlikely to go open internally. If it does, it is going to be from getting pinched, really twisted, or mangled pretty bad. Very likely if the wire is open, the insulation is also going to be damaged.
More likely cause is that a switch wire which is daisy chained all over a row/column broke loose. A lot of times two wires will be connected with solder at a switch lug. More likely to have a wire fall off one of these switch lugs than a wire to break internally for no good reason.