God condemned the cities of Sodom and Gomorrah and destroyed them by burning them to ashes.  He made those cities an example to ungodly people of what is going to happen to them.
(2 Peter 2:6 -- GW)

What happened to Sodom and Gomorrah and the cities near them is an example for us of the punishment of eternal fire.  The people of these cities suffered the same fate that God’s people and the angels did, because they committed sexual sins and engaged in homosexual activities.
(Jude 1:7 -- GW)