Death-Wish by Ray Bradbury - They wandered the dead and fragile cities, looking for the legendary Blue Bottle–not knowing what it was, nor caring, not really wanting to find it... ever...

The sundials were tumbled into white pebbles. The birds of the air now flew in ancient skies of rock and sand, buried, their songs stopped. The rivers were currented with dust which flooded across the land when the wind bade it reenact an old tale of engulfment. The cities were deep laid with granaries of silence, time stored and kept, golden kernels of forgetfulness, pools and fountains of quietude and memory.

Mars was dead.

And then out of the large stillness, from a great distance, on the stones of an old highway, there was a tiny sound. First, like an insect, and growing larger, between the cinnamon hills, and finally broadening, flattening out, the sound buzzing and humming, while something moved, growing big.

The highway trembled. The rocks ground one upon another briefly. The sound grew into a thunder which shook down avalanches of dust in the old cities.