Hiroshima observes 60th anniversary of dropping of atomic bomb on city

In Hiroshima, Japan, tens of thousands of people gathered Saturday to reflect on the explosion exactly 60 years before of an atom bomb in the sky above the city.

The city observed a moment of silence at 8:15 in the morning local time, when the world's first atomic bomb attack occurred on August 6, 1945.

In a speech at Hiroshima's Peace Memorial Park, the city's mayor called for all nations possessing nuclear weapons to abandon their arsenals.

The atomic bomb, dropped on Hiroshima by a U.S. bomber during World War II, killed more than 140,000 people. Three days later, another atom bomb killed more than 80,000 in Nagasaki, Japan.

Japan surrendered on August 15, 1945, ending World War II.