The man who stopped the tsunami

"A black wave, darker than a nightmare," is how Bob Simon describes the tsunami that hit coastal Japan in March 2011. On 60 Minutes this week, Bob travels to Otsuchi, Japan, a town literally erased by the tsunami. Out of a population of 15,000, ten percent are missing - assumed to have been washed away, as were almost all the town's homes and structures.

The citizens of Otsuchi had thought their seawall would shield them from such a disaster. A huge cement barrier at the ocean's edge, the wall was built to protect the town from just this kind of calamity. But the wall was just over 30 feet high and the tsunami wave was 50 feet. In the end, the wall took a hit as hard as the town -- Bob says it fared no better than a child's sandcastle on the beach.

Watch Bob Simon's full "60 Minutes" report here.

A few hours up the coast from Otsuchi, in the village of Fudai, residents had complained about their seawall when it was built; they said it was too high and blocked their view.

When Bob and producer Draggan Mihailovich visited Fudai after the tsunami, however, no one was complaining any more because this seawall had done its job. The very wave that demolished Otsuchi had barely touched Fudai. One villager said that the only water to touch the town was the spray on the wind.

What made the difference? Height. The seawall at Fudai is 50 feet high and could holdback a wave of the same size. On 60 Minutes Overtime this week, we tell the story of the wall that worked. It's a story with a hero: a man who was determined to hold back the waters.

As you'll see from watching the "60 Minutes" and the "Overtime" tsunami pieces this week, the difference between surviving and being destroyed by this wave of water came down to a matter of feet.

Decades ago, towns along the northeast coast of Japan began erecting seawalls to withstand waves of about 30 feet--the height of a terrible tsunami that struck in 1933.

Kotoko Wamura was the mayor of Fudai when the town began planning its seawall in the 1960s. Wamura had been a young man when the 1933 tsunami wiped out Fudai, and the memories made him determined not to let it happen again. Wamura also remembered family stories about the tsunami of 1896, which had been even bigger: 50 feet.

When it came time to draw up plans for the Fudai seawall and a later floodgate, Wamura insisted they both be 50 feet high. Many of the villagers were furious, unconvinced they needed a wall that was so expensive and so ugly, blocking their ocean view. But Wamura wouldn't back down. Fudai got the tallest seawall on the whole northeast coast.

Mayor Wamura was not alive to see his wall protect the people who live in its shadow. He died in 1987, but today he is a hero to all the villagers whose lives he saved.