Alma 16:11

11 Nevertheless, after many days their dead bodies were heaped up upon the face of the earth, and they were covered with a shallow covering. And now so great was the scent thereof that the people did not go in to possess the land of Ammonihah for many years. And it was called Desolation of Nehors; for they were of the profession of Nehor, who were slain; and their lands remained desolate.

The city smelled as bad after it was destroyed as it reeked of wickedness when they were alive.