World War II Billboard at Oak Ridge National Laboratory–Whose son will die in the last minute of the war? Minutes count!

The photo below shows a worker finishing up work on a billboard erected near Oak Ridge National Laboratory, where research on the atomic bomb was underway.

World War II Billboard - Whose son will die in the last minute of the war? Minutes count!
World War II Billboard – Whose son will die in the last minute of the war? Minutes count!