Why after destroying the 4 cities with fire from heaven, does Hashem proceed to flip them? What purpose does this accomplish?
וַֽ"ה הִמְטִ֧יר עַל־סְדֹ֛ם וְעַל־עֲמֹרָ֖ה גָּפְרִ֣ית וָאֵ֑שׁ מֵאֵ֥ת ה מִן־הַשָּׁמָֽיִם: וַיַּֽהֲפֹךְ֙ אֶת־הֶֽעָרִ֣ים הָאֵ֔ל וְאֵ֖ת כָּל־הַכִּכָּ֑ר וְאֵת֙ כָּל־יֽשְׁבֵ֣י הֶֽעָרִ֔ים וְצֶ֖מַח הָֽאֲדָמָֽה׃
And the Lord caused to rain down upon Sodom and Gomorrah brimstone and fire, from the Lord, from heaven. And He turned over these cities and the entire plain, and all the inhabitants of the cities, and the vegetation of the ground. (Bereishis 19:24-25)