Gawker.com notes that a bar in New York's Financial District has a sign in its window advertising its happy hour that reads, "The happiest Happy Hour south of Ground Zero." (There's a photo if you follow that link.)
Okay, I saw it and thought... ick. I expect a lot of people react that way. It's not what I'd stick in the window if I were the proprietor - hey, let's attract customers by reminding them of the most horrible day in the city's history!
But then, I'm not a New Yorker. Maybe I'm wrong. Maybe New Yorkers have heard "Ground Zero" so many times that it's lost that power. Maybe it's just another place name ("turn left when you pass Ground Zero and you can't miss it!")
I honestly don't know (and maybe some reader in New York can venture an opinion). But it does occur to me that Hiroshima and Nagasaki are mostly referred to these days as cities in Japan where people live and work, Dachau is a town in Bavaria, and Bull Run is a suburban area outside of Washington, not just the place where a bloody civil war began and thousands were killed and wounded.
When do these names and phrases become part of our general vocabulary, with their connotations of tragedy receding into the background? At what point can you describe your location as "south of Ground Zero" without offending people?