(God rained brimstone and fire from the sky upon Sedom and Amora -- Bereshit 19:24)
"Vatabet ishto me'acharav, vatehi netsiv melach."
([Lot]'s wife looked behind [as she fled], and behold [the city] was a pile of salt -- Bereshit 19:26, according to Ralbag/Gersonides)
Where did the brimstone with which God scoured the streets of Sedom and Amora come from?
From the charcoal that the people of the Cities used to mark everything on earth as someone's possession, never to be shared or gifted.
Where did the fire with which God cauterized the soil under the houses of Sedom and Amora come from?
From the hearths and cookfires that the people of the Cities locked within their homes and courtyards, barred to access by cold and shivering strangers.
Where did the salt with which God pulverized and buried the remains of Sedom and Amora come from, forming the seabed of the Yam Hamelach/Salty Sea?
From the mines and the resource fields where the people of the Cities harvested basic necessities, priced so only the wealthy could obtain them.
That which is released from heaven exists in parallel with that which is released from earth, measure for measure, as we read in the story of Noach:
"Nivke'u kol ma'ayanot tehom rabah va'arubot hashamayim niftachu. Vayehi hageshem al ha'arets arba'im yom ve'arba'im laila."
(All the fountains of the deep broke open, and the curtains of the sky parted. It rained upon the earth for forty days and nights -- Bereshit 7:11-12)
It is an upwelling of sin that brings on the flood of destruction. There is a cycle in the world, as the Creator relates to us as we relate to others. The trees transpirate and the clouds gather, the good and evil that we do returns to us. All has consequences, though we are not yet wise enough to connect all the dots..
"Ki ka'asher yered hageshem vehasheleg min hashamayim, veshama lo yashuv, ki im hirva et ha'arets veholida vehitsmicha venatan zera lazorea velechem laochel: ken yihyeh devari asher yetsei mipi lo yashuv elai rekam ki im asah et asher chafatsti vehitsliach asher shelachtiv"
(Just as the rains and the snows fall from the sky and do not return without saturating the earth that it may sprout and blossom, giving seeds to the sower and bread to the diner: so will these words exiting my mouth not return to me empty, but they will complete their mission and accomplish my will -- Yeshayah 55:10-11)