Parents look for answers year after Japan tsunami

(CBS News) ISHINOMAKI, Japan - On March 11, 2012, one year will have passed since the earthquake and tsunami that devastated Japan. At least 16,000 people were killed in an instant, but over 3,000 people remain missing.

Complete coverage: Disaster in Japan
PICTURES: Japan tsunami recovery: Then and now

A year may be a long time, but not to those who lived it. No place was harder hit by the tsunami that Ishinomaki, where 3,182 people died. Crews are still searching for 533 missing victims.

The town lost many young residents at the Okawa school site. Seventy-four children and 10 teachers died when they were swept away by the tsunami.

"Why are they alive and my child had to die?" Sayomi Shito told CBS News correspondent Bill Whitaker. Her 12-year-old daughter Chisato was one of the people who died at the school. Her mother still visits the site every day, even though it is painful.

One of the biggest tragedies of the story is that the children and teachers were following standard earthquake emergency instructions, which is what may have lead to their death. When the earthquake hit, the schoolchildren ducked under their desks. Afterwards, they went out to the open, low-level playground to be safe from aftershocks.

It was there that the tsunami wave washed in and claimed so many lives. Right next to the field was a hill. Naomi Hiratsuka -- the mother of another 12-year-old victim -- told Whitaker she wondered why the students didn't climb to higher ground. Shito agrees with her, and has directed her anger at the school. She said one time a school official told them it was the children's "destiny" to die.

That comment enraged parents so much that they shouted at school officials, something that is rarely done in Japan. A video shows one father slamming a shoe on a table, claiming that it was all that was left of his daughter. The only teacher to survive the tsunami is shown hanging his head in shame.

The shrine Sayomi Shito built for her daughter, who died in the tsunami
Shito has built a shrine for Chisato out of her daughter's favorite things. Even a year later, the mother is still in agony.

Hiratsuka channeled her rage and grief into searching for her daughter's body, learning how to operate a heavy excavator so she could search in more places. Even after her daughter's body was found, she still continues to look for others.

"Nobody wants their child left behind in the mud," she said.

The mother said she is finding the strength to go on. "My daughter's dream is to be a teacher, so I have to go back to teaching. That is my goal," she said.