(UNKNOWN) (through translator): We are acting -- assuming that a meltdown has occurred. And with reactor number three, we are also assuming the possibility of a meltdown.
AMANPOUR: As we continue to make our way towards the quake zone, we wonder how much of the country has been affected by this kind of chaos and destruction. We're about to find out, as we arrived at the airfield.
(on-screen): The helicopter is taking on fuel, and we're going up to the Sendai earthquake zone. Japan is not a massive country, but part of that Sendai area is quite remote. Some of the roads have been damaged. There are mountains in the greater area around there. And that's hampering not just assessment, but also relief and the delivery of supplies.
(voice-over): On the hour-long ride to the city of Sendai near the epicenter, little evidence of the earthquake. Much of the countryside appears unscathed. And even as we approach Sendai, we see the city still standing.
But as the chopper turns to the coast, the full extent of the devastation reveals itself. Huge swaths of land along the coast remain underwater. We fly past this massive plume of black smoke, billowing 3,000 feet into the air. The petrochemical plant below has been burning since the earthquake struck. And oil is spilling into the water.
Japanese rescue operations are being launched by sea and by land. And search-and-rescue teams are coming to help them from across Europe, the United States, Australia, and South Korea.
(UNKNOWN): We do know that the longer time goes on, the less likely it is we'll find survivors, so the imperative is for us to get there as soon as we possibly can.
AMANPOUR: And a team of Japanese workers which had gone to New Zealand to help with recovery efforts after last month's 6.3 earthquake here are now heading home.
(UNKNOWN): We have heard quite severe situation in Japan, and we are going back to Japan today. We have heard quite severe situation in Japan, and we are going back to Japan today.
AMANPOUR: Already we've seen dramatic rescues taking place this weekend, workers searching through rubble and rescuers transporting survivors to safety, but the fear here among so many is palpable.
(UNKNOWN) (through translator): My husband hasn't come here yet. He left home a little later than me. Our house was swept away.
AMANPOUR: They search the names of the missing.
(UNKNOWN) (through translator): My son might have been engulfed by the tsunami. I hope he's taking shelter somewhere.
AMANPOUR: And this young mother can only hope that her worries are unfounded.
(UNKNOWN) (through translator): That's my name. The tsunami swept away my car, and my house was burned down by the fire afterwards. My sons must be very worried about me. The phone lines are bad, and I could only send out one text message. I just want to let my family know that I'm alive.
AMANPOUR: Best of all, scenes like this one, a man reunited with his wife.
(UNKNOWN) (through translator): I'm so lucky to have survived.
(UNKNOWN) (through translator): I'm relieved to see him again, but I can't rejoice completely because people are still waiting to be rescued.