A visiting science fiction author, James D. Macdonald, showed a writing group at my school this story when I was in 7th/8th grade (around 1996-1997) and I can't remember the title or the author but it's always stayed with me and I'd love to find out more about it.
The gist of the story is that someone starts a job working for a news service, receiving telegrams or teletypes or similar written communiques. Pretty soon he starts receiving telegrams from a city that doesn't show up on any map, name kinda reminds me of Xanadu or something similar. The employee reads these telegrams as they describe a kind of mist enveloping this city; and to cut a short story short, the city is ultimately destroyed and no more word is received.
Really sorry if this is vague, doesn't leave much to go on.