Isshūkan mizu-dake-de ikite-itan-da-tte. (He said he lived alone for a week on just water.)

Situation 1: The Okubo family are watching TV news about a boy who got lost on a mountain and was found a week later.

母:  うわあ、あの男の子、すごいね。一週間水だけで 生きていたんだって。