Isaiah 21:9
And look, here comes a chariot of men with a pair of horsemen!" Then he answered and said, "Babylon is fallen, is fallen! And all the carved images of her gods He has broken to the ground."

Interesting that rather than rejoicing at the fall of Babylon Isaiah felt distress just a the Babylonians would have felt. Empathy for the unsaved in view of the judgment to come is a rare quality even among Christians. More common is the attitude of righteous indignation or even apathy towards the unsaved, but seldom is there actual feelings of distress over their fate.

The book of Revelation speaks of the fall of Babylon a couple of times.

Revelation 14:8  And another angel followed, saying, "Babylon is fallen, is fallen, that great city, because she has made all nations drink of the wine of the wrath of her fornication."

Revelation 18:2-8
And he cried mightily with a loud voice, saying, "Babylon the great is fallen, is fallen, and has become a dwelling place of demons, a prison for every foul spirit, and a cage for every unclean and hated bird!

"For all the nations have drunk of the wine of the wrath of her fornication, the kings of the earth have committed fornication with her, and the merchants of the earth have become rich through the abundance of her luxury."

"For her sins have reached to heaven, and God has remembered her iniquities.
"Render to her just as she rendered to you, and repay her double according to her works;
in the cup which she has mixed, mix double for her.
"In the measure that she glorified herself and lived luxuriously,
in the same measure give her torment and sorrow;
for she says in her heart, ‘I sit as queen, and am no widow, and will not see sorrow.’
"Therefore her plagues will come in one day——death and mourning and famine.
And she will be utterly burned with fire, for strong is the Lord God who judges her.