The following is from a script of "Three Years Later" which aired on April 6, 2014. Bob Simon is the correspondent. David Schneider, producer.
The hell that broke loose on March 11, 2011, was the strongest earthquake in Japan's history.
When the shaking stopped, a tsunami raced towards shore with as much fury as nature can muster. Almost all of the more than 18,000 people who died that day on Japan's northeast coast, died in the flood.
The quake didn't do much damage to the Fukushima Daiichi Nuclear Power Station but the tsunami shut down the reactors' emergency cooling systems and they started to melt down. Hydrogen gases inside the buildings then exploded spreading radiation into communities more than 25 miles away.
Today, in the town of Tomioka, the radiation levels are considered safe enough to allow people in during the day.
Loudspeakers warn visitors that they must leave by 3 p.m. We were alone on the day we were there. The disaster seems to have stopped time. The clock shows 2:46, the moment the earthquake hit and the damage to shops and homes looks like it could have happened yesterday. The stack of newspapers we found were dated March 12th, 2011 -- the day after the quake and tsunami. You can see people had to leave in a hurry -- that was the morning the government told people of this town and neighboring towns to get out quickly.
Welcome to Okuma says the sign. Population today - three years later: zero. More than 11,000 people left town that day and never returned.
Bob Simon: Would you ever want to go back to Okuma to live there again?
Norio Kimura: Yes, I would like to before I die.
Norio Kimura lived with his wife and two daughters next door to his parents. The tsunami killed his father, his wife and his youngest daughter, Yuna; a bright and cheerful 7-year-old. This is what their homes looked like before March 11th, 2011. This is what's left today. Foundations. And scraps of memories that he keeps in a small box by -- what was once -- the front door.
Norio Kimura: This is a shoe she was wearing that day, which was found in a heap of rubble six months after the disaster.
Because of radiation, Kimura can only visit his former home 10 times a year and stay only five hours. In February, his allotted day came in the middle of a blizzard.
On each visit, Kimura brings flowers to a small shrine he built to honor his family. They were among the 111 people who died in Okuma that day. The remains of 110 have been recovered. The only one still missing is Norio Kimura's daughter, Yuna. Ten times a year he goes back home to search for her.
Bob Simon: On Saturday, you were digging again in Okuma. It was snowing. It was freezing. Why?
Norio Kimura: To find Yuna of course, and also if I stopped searching or gathering her things, I will lose the connection with her. To be honest, the reason why I can live my life every day is because I have to find her and her things. I need to do this to keep my sanity.Volunteers now help Kimura dig through the piles of debris left by the tsunami. Everyone's dressed in protective clothing to limit their exposure to radiation. The digging seems futile, but on this day, Kimura unearthed clothing he says belonged to his surviving daughter, Mayu. On March 11th, the day of the tsunami, Kimura made a mistake for which he will never forgive himself. He was at work on a farm and he stayed there.
Bob Simon: Did you think then, that there would be a tsunami?
Norio Kimura: There was a radio at my work and my boss told me that the tsunami was going to be three meter tall. My house is five to six meters above sea level, so I was convinced that our home would be fine, and did not worry about it at all after that.
Bob Simon: Do you think there is anything you could have done to save your family?
Norio Kimura: I should have gone home right away. I regret believing the information easily while my family was in life threatening danger. Even now, I say to myself, what was I thinking?
When radiation forced the evacuation of Okuma, the town leader told Norio Kimura to stop searching for the missing and start caring for the living.
Bob Simon: So he and his daughter moved here to the Japanese Alps where the brisk air and the snow capped mountains made radiation and tsunamis difficult to imagine.
Kimura has traded farming for a guest house he's planning to open. His daughter, Mayu, talks about her mother more than her missing sister and doesn't ask why her father continues searching for her. Their new mountain home is 2,000 feet above the perils of the sea and 180 miles from the Fukushima plant.
Ghost towns surround the plant now, but three years later, there are still more than 4,000 workers there, all of them wearing layers of protection. Because of the exposure to radiation, the men in this building are only allowed to work two and a half hours a day. They're not producing any electricity. They're just cleaning up.
Bob Simon: Were TEPCO workers adequately trained to handle the emergency?
Dr. Yoichi Funabashi: I don't think so.
Within months of the accident, Yoichi Funabashi, a former newspaper editor, headed an investigation into what went wrong and why. It was the only investigation not sponsored by the government and its conclusions were brutal.
Dr. Yoichi Funabashi: I was very much concerned about the government not telling the truth to the public.
The revelations in Funabashi's report added to the public's anger and dismay. He wrote that, from the beginning, the government had conspired with the industry to convince people that nuclear power is safe.
Bob Simon: --so the government effort at the time was to convince people that there was nothing to worry about?
Dr. Yoichi Funabashi: Exactly. Nothing to worry about. Don't worry. 'Kay, even don't prepare for that-- the-- severe accident, 'kay. Because that would cause that unnecessary unease and unnecessary misunderstanding.
Bob Simon: And there's no reason to prepare.
Dr. Yoichi Funabashi: No reason to prepare. So this avoidance ultimately translated into unpreparedness.
Lake Barrett: Mother Nature threw a real curve ball to the Japanese with that huge tsunami.
Last year, TEPCO hired American nuclear engineer Lake Barrett as an advisor. Barrett directed the cleanup at the Three Mile Island nuclear plant after its accident in 1979.
Bob Simon: It's estimated that the cleanup is going to take 30-40 years. To a layman, that sounds very, very long. Can you explain why that's--
Lake Barrett: To me, that's not long at all. That's what I would expect for that kinda thing. It's a huge challenge. It's a big onsite mess that they have to clean up. And it's gonna take 'em decades to do it. It took us 10 years to do Three Mile Island, and Three Mile Island accident was much simpler-- than they have at Fukushima.
Bob Simon: Are they where you thought they would be three years later?
Lake Barrett: I'd hoped they'd be further along. It's been challenging-- technically, it's been challenging culturally and politically for them. But they're making good progress now.
Bob Simon: Sounds like you're being a little diplomatic.
Lake Barrett: Well, decision making process in Japan is complicated.
Decision-making in Japan requires consensus and reaching consensus often takes a very long time.
The most difficult job will be to dismantle the melted reactors, but radiation is too high for workers to get there. For now, TEPCO is inundated with groundwater that leaks into the reactors and gets contaminated. Every day, 100,000 gallons of radioactive water has to be pumped out before it reaches the ocean. TEPCO is filling storage tanks almost as fast as it can build them and they're notorious for leaking.Another enormous cleanup is happening outside the plant. Entire communities are being cleared of contaminated materials that will have to be stored for generations. This part of Japan is known for its agriculture, but the only crop growing now is the multitude of black bags holding the radioactive waste, filling the empty spaces in towns like Okuma.
Now, some of the kids from Okuma live and go to school 70 miles away.
Bob Simon: How many of you would like to go back to Okuma, raise your hand. [Hands go up] Everybody. How many of you think you will go back to Okuma? [Kids look around - no hands up.]
Bob Simon: What's keeping you from going back to Okuma now? You can tell me.
Kid: Because there's a lot of radiation... there's a lot of radioactive material there.
These kids will be middle aged before the cleanup is finished. Their homes could have been rebuilt quickly if it had just been an earthquake and a tsunami. It's the manmade disaster which will take decades to repair. This is the class that Norio Kimura's daughter, Yuna, would have been in if she were alive. Her friend Kurea remembers they ate lunch together.
Bob Simon: Where is she now?
Kurea: In Okuma. She's lonely, being alone in the town of Okuma all this time. I think she must be lonely.
About a third of the residents from Okuma decided to stick together and moved into what the government called "temporary housing." Temporary is lasting a long time.
The three generations of Kimuras that once lived together are now split apart. Norio and his daughter live in Nagano, five hours away from his mother, Tomoe. She lives in the temporary housing, alone in a cold and cramped room furnished with photographs.
The Kimuras, like many Japanese, have a strong connection to their dead and feel obliged to help them be at peace. As long as the dead are in limbo, so are the living.
Bob Simon: You've lost so much of your family, why aren't you together with your son now?
Tomoe Kimura: I'm with my husband's ashes now. Once I find a proper place to put him, I'd like to go to Nagano.
Bob Simon: What do you think the right place would be?
Tomoe Kimura: Our family cemetery in Okuma is contaminated with radiation now. I could come back twice or three times a year to burn the incense for him, but my grandchild would not be able to come. I don't want to keep him where his grandchild whom he used to adore so much can't even come to visit.
Ten times a year, Norio Kimura visits his ancestors in the family cemetery, a place where he thought he would be laid to rest one day and where his children would come to visit him. But he won't find any peace, he says, until after he finds Yuna.
Bob Simon: Do you think that there is any chance of ever finding your daughter?
Norio Kimura: I know that the chance is very slim, but no matter how slim the chance is, I still cannot stop. From outside looking in, I know that this is very unlikely. But I still can't stop even if I cannot ever find her.