Genesis 19:26 (KJV)

And he said unto him, See, I have accepted thee concerning this thing also, that I will not overthrow this city, for the which thou hast spoken.

Haste thee, escape thither; for I cannot do anything till thou be come thither. Therefore the name of the city was called Zoar.

The sun was risen upon the earth when Lot entered into Zoar.

Then the LORD rained upon Sodom and upon Gomorrah brimstone and fire from the LORD out of heaven;

And he overthrew those cities, and all the plain, and all the inhabitants of the cities, and that which grew upon the ground.

And Abraham gat up early in the morning to the place where he stood before the LORD:

And he looked toward Sodom and Gomorrah, and toward all the land of the plain, and beheld, and, lo, the smoke of the country went up as the smoke of a furnace.

And it came to pass, when God destroyed the cities of the plain, that God remembered Abraham, and sent Lot out of the midst of the overthrow, when he overthrew the cities in the which Lot dwelt.

And Lot went up out of Zoar, and dwelt in the mountain, and his two daughters with him; for he feared to dwell in Zoar: and he dwelt in a cave, he and his two daughters.

And the firstborn said unto the younger, Our father is old, and there is not a man in the earth to come in unto us after the manner of all the earth: