Technology breaking down, No-one knows how to fix it

the story, or maybe part of a larger work, I am thinking of involves a portrait of either

a.) an alien race

or more likely

b.) the future human race

this race relies entirely on their technology and have biologically evolved with it's use, everything provided. some observer, perhaps a space traveler or a time traveler, or perhaps just a narrator even, is watching this race or arrives on them somehow through the course of the story- if there was anything before it, I know not what.

anyhow, they no longer really understand HOW the technology works. to them it is just part of nature, but it is breaking down, it is failing, and they are trying to show the observer, so he thinks, that they are worried and frail and afraid for they do not understand.

anyone have any ideas? I feel like it was in a compendium of science fiction short stories from the 1960's perhaps, and I have no idea who the author might be. thanks!