The Lord has many ways that he uses to destroy the wicked, such as earthquakes, floods, war, famine, floods and famine, but he reserves destruction by fire for the most wicked, so that there is "neither root nor branch" left (3 Nephi 25:1).

Here's some other cases where wicked people are destroyed by fire. In each case, there are no righteous remaining at all.

Sodom and Gomorrah

See Genesis 19:24-25,27-28.

Again, the destruction is complete, "all the plain, and all the inhabitants of the cities, and that which grew upon the ground."

Nephite cities

There were lots of cities burned by fire: Zarahemla, Laman, Josh, Gad and Kishkumen.

The story is in 3 Nephi 9:3,9-11.

Here are the reasons for the city of Jacobugath specifically:

• "their sins and their wickedness, which was above all the wickedness of the whole earth"
• "their secret murders and combinations"
• "it was they that did destroy the peace of my people"
• "and the government of the land"
• "casting out the prophets"
• "stoning those whom I did send"
• "they did cast them all out"
• "there were none righteous among them"
• "I did send down fire and destroy them"
• "that their wickedness and abominations may be hid from before my face"
• "that the blood of the prohets and the saints whom I sent among them might not cry unto me from the ground against them"

Second Coming

Malachi prophesied that at the Second Coming, all the wicked shall be burnt. See Malachi 4:1.