Pres. Obama visits HiroshimaPresident Barack Obama visited Hiroshima today and paid respect to the 140,000 lives killed by the atomic bomb dropped on the city in 1945. He became the first sitting US president to do so. He called for a world without nuclear weapons but did not apologize for the attack. CaptionUS President Barack Obama hugs Shigeaki Mori (front), a survivor of the 1945 atomic bombin