John Gills Exposition of the Bible Commentary - Genesis 19:25
And he overthrew those cities ,.... Of Sodom, Gomorrah, Admah, and Zeboiim: very probably at the same time that this fiery tempest was in the heavens, there was an earthquake which overthrew the cities; and so Strabo F8 Geograph. l. 16. p. 526. makes the lake, which is now the place where they stood, to be owing to earthquakes and eruptions of fire, and of hot bituminous and sulphurous waters; and says nothing of fire from heaven, which yet Tacitus and Solinus do, being unacquainted... read more
John Gills Exposition of the Bible Commentary - Genesis 19:24
Then the Lord rained upon Sodom, and upon Gomorrah, brimstone and fire from the Lord out of heaven. And not upon those two cities only, but upon Admah and Zeboiim also, see Deuteronomy 29:23 ; this was not a common storm of thunder and lightning, with which often there is a smell of sulphur or brimstone; but this was a continued shower of sulphurous fire, or of burning flaming brimstone, which at once consumed those cities and the inhabitants of them; and the land adjacent being... read more