Burn the town

Southeast of the Dead Sea what is thought to be the ruins of Sodom and Gomorrah have been discovered. Known as Bab edh-Dhra, discoveries in the cemetery provided clues to its destruction. Excavators determined that buildings for burying the dead were burned from the top down.
 
This agrees with the biblical account: "Then the Lord rained upon Sodom and upon Gomorrah brimstone and fire from the Lord out of heaven" (Genesis:19:24Then the LORD rained upon Sodom and upon Gomorrah brimstone and fire from the LORD out of heaven;
See All...). The reasonable conclusion is that burning debris fell on the buildings from the air. This agrees with the archaeologist's findings.
 
Geologist Frederick G. Clapp visited the area in 1929 and 1934 and recorded fault lines along the east and west sides of the Dead Sea. Others have noted that earthquakes are common to the area. Clapp's research revealed asphalt and petroleum accompanied by natural gas in this region. Genesis:14:10And the vale of Siddim was full of slimepits; and the kings of Sodom and Gomorrah fled, and fell there; and they that remained fled to the mountain.
See All... notes that the valley of Siddim was full of tar pits or naturally occurring asphalt. Archaeologist Bryant Wood speculates that, "these combustible materials could have been forced from the earth by subterranean pressure brought about by an earthquake resulting from the shifting of the bounding faults. If these combustibles were ignited by lightning or some other agency as they came spewing forth from the ground, it would indeed result in a holocaust such as described in Genesis 19" (Bryant Wood, Associates for Biblical Research, 1995, 2001). After shooting up into the sky, the burning material only had one place to go -- down to the rooftops of Sodom.