It was initially written as a short story and later incorporated in "The Martian Cronicles". There was also a great dramatisation of it on Dimension X, which can be found on The Internet Archive.
It is hard to believe it was written in 1950. Sure our vision of what the tech looks like might have changed a bit, but not the essence of the story. It is a truly chilling vision and it looks increasingly plausible with every year.
There will come soft rains and the smell of the ground,
And swallows circling with their shimmering sound;
And frogs in the pools, singing at night,
And wild plum trees in tremulous white,
Robins will wear their feathery fire,
Whistling their whims on a low fence-wire;
And not one will know of the war, not one
Will care at last when it is done.
Not one would mind, neither bird nor tree,
If mankind perished utterly;
And Spring herself, when she woke at dawn,
Would scarcely know that we were gone.