Cold side of faucet spontaneously stopped working?

I have a double sink on the wall that is shared with the garage attic. All of a sudden this morning, the cold water won't work on either faucet, but the hot side is fine? Could it be frozen? I doubt that both faucets work stop working exactly the same way in the same night unless its the feed... Most importantly, when it thaws out, will I have a leak somewhere or should everything go back to normal?