The Crawlers

"Survey Team" is the story of two planets, first published in Fantastic Universe (May 1954).
"Survey Team" tells of a designated four man group of space travelers chosen to find another planet on which humankind can survive., since the once good green earth has been all but destroyed, rendered uninhabitable by nuclear war. The few remaining humans live miles beneath the surface, their resources depleted, their survival only a matter of time. Could Mars be the place they are looking for? The "survey team" has been chosen to find out.
The first thing they see when they arrive on Mars is a ruined city, and in their course of exploring the ruins the discover some disturbing truths, not only about the history of Mars, but of the the nature of humankind itself.
This is a disturbing, bleak tale. It is perhaps a little heavy-handed, particularly at the end.