[rlpiii]

Some wire failure possibilities:

1. Rodents, roaches, termites or something else eating at your wire.
2. Defective speaker wire that finally failed.
3. House shifting problems that pinched off or partially severed your connection, including any possible earthquakes in your area.
4. New construction or even just hanging new pictures where the nail could have punctured the speaker wire.
5. Heat damage - some wire has outside jackets with low melting points and if the wire is too close to heat sources (lights, heaters, hot water pipes, etc.) it will melt and expose the pos. and neg. sides to each other.