The following podcast contains some graphic descriptions which some listeners might find upsetting. Leo Salard has never felt so powerless in his life. He knows the bomb is going to be used, bringing untold death and destruction.

Salard has created a petition to the American president, going on the record against

the use of the bomb.

But he is under no illusion that this will stop the outcome

that now seems inevitable. The chain reaction is in motion. All he can do is

wait. Finally, the news he has been awaiting and dreading arrives.

Scientists, British and American have made the atomic bomb at last. The first one was dropped on a Japanese

city this morning. President Truman gave the news this afternoon in a statement

from the White House.

Up until the moment it was dropped, the atomic bomb was the world's best kept secret.

Even some members of the flight crew did not know what they were being sent to drop until they were

airborne.

President Truman added that the atomic bomb opens up a new and revolutionary increase in destruction

to supplement the growing power against Japan. This atomic bomb the President added is a harnessing of the basic

powers of the universe. The force from which the sun draws its power has been loosed against

those who brought war to the Far East.

All over the world, there's a sense of shock that this new weapon even exists,

which only grows when its devastating impact is revealed.

We have entered a new era, the nuclear age. My name is Emily Strasser.

From the BBC World Service, this is the bomb.

Episode 7, the Doomsday Clock. The There was just a single bomber in the sky. Nobody had time to run for shelter. Nobody had time to duck and cover. Oh, I found myself pinned under the collapse building totally dark and silent strangely.

On the day the atomic bomb falls in Hiroshima,

...