The story "There Will Come Soft Rains," by Ray Bradbury, opens in a house devoid of humans. As the story progresses, the location of the people for whom the house furiously works becomes a source of increasing tension. Breakfast is made and cleaned away. Robot mice clean all signs of dust. A dog comes in, dies, and is cleaned away within minutes. A nursery projects calming animal scenes. Evening baths are run.
And, still, there are no humans.
Finally, the house begins to recite a favorite poem of Mrs. McClellan, who is seemingly supposed to be home. The poem begins, "There will come soft rains," and this is where the title of the story originates.
In this poem, nature is seen as enduring force in the absence of humans. The poem makes a strong assertion in conclusion: Nature doesn't need humans in order to maintain itself. "Neither bird nor tree" requires humans in order to survive, and "Spring herself" would not notice if humans disappeared completely. Frogs would still "sing," seasons would still change, and rains would still fall.
This greatly explains what has happened to the humans who should live here. Their images are burned into their house, likely as a result of a nuclear war. They have disappeared from existence, and, just as the poem predicts, nature keeps moving forward. In fact, nature itself causes the fire which destroys the house, showing that in the end, the forces of nature are much more enduring than anything humankind can create.