‘Then Yahweh rained on Sodom and on Gomorrah brimstone and fire from Yahweh out of heaven, and he overthrew those cities and all the Plain, and all the inhabitants of the cities, and all that grew on the ground.'
The possibility from the description is that we are to see here volcanic action. But we are to recognise that it had been restrained by Yahweh until that very moment. Another strongly suggested alternative is that of a tectonic earthquake resulting in the release of inflammable gases, asphalt and petroleum, ignited by the heat. It may have resulted in the expansion of the Dead Sea at the Southern end. The Dead Sea area is today rich in deposits of asphalt and sulphur. There are references in later extra-Biblical literature to some kind of disaster in this area.
The sites of these cities are as yet unknown although some postulate them as being under the Southern tip of the Dead Sea. We must consider that the configuration of the land may well have altered drastically as a result of the disaster and the passage of time. Suggested mention of the cities at Ebla is still very much open to question.
The suggestion that ‘and Gomorrah' is a later addition overlooks the fact that Sodom is being centred on because of the presence of Lot, and that they are regularly seen as a pairing (Genesis 13:10; Genesis 14:10-11, compare how only the king of Sodom is mentioned later, Sodom is clearly the primary city; Isaiah 13:19; Jeremiah 49:18; Jeremiah 50:40; Amos 4:11). In fact the whole Plain of Jordan clearly comes under judgment. Yahweh knows the true condition of all the inhabitants. Lot was the exceptional feature that required testing.
If Lot still possesses servants, flocks and herds, they too perish in the conflagration. But his failure to consider them may suggest that by this time Lot is a merchant and no longer involved with herding. The incident with the five kings, when his possessions were all appropriated, may have led him to invest in things which could be more closely watched and hidden. If he does still have servants the indication is that they too have become involved in the perversions and religion of Sodom.