Everyone seems to forget there were five cities of which FOUR CITIES destroyed at that time. Sodom, Gomorrah, Admah and Zeboiim. Zoar got a reprieve since Lot fled there for a short while, then away as the inhabitants were so vile.
In other non-biblical history there have been quite a few cities destroyed by natural causes. Herculanium, Pompeii, Saint-Pierre, Martinique. I have read the governor of Saint Pierre loved to parade crucified pigs through his streets before the Big Boom took him and the city out.
Genesis 13 mentions Zoar, and notes that the whole area was like the “garden of the LORD”. Apparently the Dead Sea wasn’t dead before the destruction.