The atomic bombings of Hiroshima on August 6, 1945, and Nagasaki three days later brought a scale of destruction the world had never seen. Many who survived the blasts died in the weeks, months and years that followed.

Mayor Kazumi Matsui called on leaders to heed the lessons of Hiroshima and Nagasaki and warned of the consequences of the global trend towards a military buildup.

This week marks the 80th anniversary of President Harry Truman's fateful decision to drop atomic bombs on the Japanese cities of Hiroshima and