President Barack Hussein Obama is the first US president to visit Hiroshima, Japan.
Students of history and wars know the devastation which was caused when nuclear bombs were dropped on Hiroshima and Nagasaki in 1945.
Obama visite Hiroshima's Peace Memorial Park which was set up to commemorate and remember the people who died during that time due to nuclear weapons.
At the Peace Memorial Park, Obama called for "world without nuclear weapons". He proceeded to say what happened on that fateful day.
"71 years ago on a bright, cloudless morning, death fell from the sky and the world was changed."
"A flash of light and a wall of fire destroyed a city, and demonstrated that mankind possessed the means to destroy itself,"
"Why do we come to this place, to Hiroshima? We come to ponder the terrible forces unleashed in the not so distant past. We come to mourn the dead ... their souls speak to us and ask us to look inward. To take stock of who we are and what we might become."
"The scientific revolution that led to the splitting of an atom requires a moral revolution as well," Obama said. "That is why we come to this place."
"The world war that reached its brutal end in Hiroshima and Nagasaki was fought among the wealthiest and most powerful of nations".
"Those civilizations have given the world great cities, magnificent art, thinkers that advanced ideas of harmony and truth, and yet the war grew out of the same base instinct for domination. Conflicts can cause conflicts among the simplest of tribes."
"The world was forever changed here but today the children of this city will go through their day in peace. What a precious thing that is. It is worth protecting."
Obama signed the guest book saying that he hoped that the world can find courage and work together to ensure there is peace and that the world no longer harbours nuclear weapons.
He laid a wreath on at the museum in the company of Japan's Prime Minister Shinzo Abe.
Obama spoke for about 20 minutes and did not apologize for the US action to use nuclear bombs to speed up the end of WWII. There had been speculation that he would not apologize for the US' role in the attack on Hiroshima.
Obama was not expected to apologize for the U.S. action to hasten the end of World War II and he did not during his 20-minute-long remarks.
Obama met many war survivors and one gentleman, Sunao Tsuboi, said he "never imagined (the President) would come while I am alive. "We do not need apologies. I hope that he [Obama] will present in Hiroshima what is good for the happiness of humankind. I would like [us] to join hands with each other through the power of reason and beyond hatred".
It is estimated that 100,000 to 150,000 people lost their lives in Hiroshima. They included American soldiers but mostly Japanese people.
It is estimated that 40,000 to 80,000 lives perished in Nagasaki.
The Uranium laded bomb was dropped on Hiroshima on August 8, 1945.
A Plutonium bomb was dropped on Nagasaki on August 9, 1945.
Six days after the bombing of Nagasaki, August 15, 1945, Japan surrendered to the Allies.
The following month, Japan signed officially the surrender which ended WWII on September 2, 1945.