The tsunami-hit Okawa Elementary School in Ishinomaki, northeastern Japan March 28, 2011. Photograph: Yuriko Nakao/Reuters In 2011 a tsunami engulfed Japan’s north-east coast. More than 18,000 people were killed. Six years later, in one community, survivors are still tormented by a catastrophic split-second decision The earthquake that struck Japan on Friday 11 March 2011 was the fourth most power