Josh, fire was sent down to destroy the city and its inhabitants for wickedness in casting out the prophets and saints that were sent among them.
is burned, 3 Ne. 9:10-11
10 And behold, the city of Laman, and the city of Josh, and the city of Gad, and the city of Kishkumen, have I caused to be burned with fire, and the inhabitants thereof, because of their wickedness in casting out the prophets, and stoning those whom I did send to declare unto them concerning their wickedness and their abominations.
11 And because they did cast them all out, that there were none righteous among them, I did send down fire and destroy them, that their wickedness and abominations might be hid from before my face, that the blood of the prophets and the saints whom I sent among them might not cry unto me from the ground against them. (3 Nephi 9)