1) The cities of Sodom and Gomorrah were destroyed by fire and brimstone from God for their evil acts, including killing Lot's daughter by covering her in honey and having bees sting her to death.
2) Angels rescued Lot, his wife, and daughters from the destruction and told them not to look back at the cities as they were being destroyed.
3) Lot's wife disobeyed and looked back, and she was turned into a pillar of salt as a result.