richter scale. then a huge tsunami crashing up the coast. it was like watching a disaster movie, this one horribly real. and john terry's son zach was now right in the middle of it. >> what did you think? >> unreal. this can't be happening. are you sure it's where zach is? are you sure it's in the same region? we were looking at maps, and everything was pointing to, yeah, it's exactly where zach is. >> we just prayed. >> enormous waves you see here were hitting noda and kuji, the towns where zach and georgia were teaching. the frantic calls began, to no avail. >> what happened when you tried his phone? >> it would say all circuits are busy and you'd get a busy signal. >> then the minutes went by. >> uh-huh. >> then an hour and two hours. what did that feel like? >> hell. >> as a parent, you never think, oh, my child has been killed. out don't think that. you just wait. you just wait and just pray for the best. >> remember, zach had wanted to come home months earlier, but terry and john had encouraged him to stay, to live up to his commitment. >> how much did you beat yourself up about that? >> i did. >> seemed r