Name of either a sci fi short story or a book where if the characters

[pm]

walk off of "the path" they change how? the world looks... and at the end of the story someone does walk on the path, kills an insect or bug comes back to earth and re reads a sign he saw in the office and the words are all spelled differently.

[soup]

It's called 'A Sound of Thunder' by Ray Bradbury.


http://en.wikipedia.org/wiki/A_Sound_of_Thunder