Revelation 18:8

Therefore shall her plagues come in one day
The seven last plagues, which will be in a very little time executed upon her, very speedily and very quickly, one after another, if not all together; and particularly the fifth vial may be respected, as well as the plagues that follow; see ( Isaiah 47:9 )

death;
not the second death, which will not be till after the decisive battle at Armageddon, when the beast will be taken, and cast alive into the lake which burns with fire and brimstone, which is the second death; but either the pestilence, which is called so, ( Revelation 6:8 ) or rather death by the sword, war, which will be brought upon her, and in which she and her children will be slain with the sword:

mourning;
for the loss of her children, the destruction of the city of Rome itself, the seat of the beast, and for the darkness of his kingdom, the inhabitants of which shall be in such pain, as to gnaw their tongues for it:

famine;
which generally attends war, at least sieges; and it looks as if Rome would be besieged awhile before it is destroyed, which will produce a grievous famine in it; this is opposed to her living deliciously, as well as the two former are to her notion of sitting a queen for ever, and knowing no sorrow:

and she shall be utterly burnt with fire;
the burning of Rome has been attempted several times, by different persons, and has been burnt in part, but not wholly, (See Gill on Revelation 17:16) but now it will be entirely destroyed by fire; either by fire from heaven, as Sodom and Gomorrah were; or by fire breaking out of the earth, it being very manifest that there are volcanos, burning mountains, and subterraneous fires in those parts, which seem to be so many preparations in nature for the burning of that city; or rather by the ten kings, who will set fire to it; and it may be by all these ways. The Jews have a notion, that, at the coming of the Messiah, Rome will be burnt ^F1, as Sodom has been; you will find, say they {b}, that of Sodom and of that kingdom (Rome, of which they are speaking, and which they afterwards call the fourth kingdom), it is decreed concerning them both, that they "should be burnt with fire"; of Sodom, ( Genesis 19:24 ) and of the fourth kingdom (Rome), ( Isaiah 34:9 ) .

for strong is the Lord God that judgeth her;
the Alexandrian copy reads, "that has judged": and so the Syriac and Arabic versions; that is, has purposed and determined her destruction, and therefore it is unavoidable; he that has resolved upon it, and foretold it, and has condemned her to it, is the Lord God Almighty; and he is able to execute the sentence determined and pronounced, and it is impossible she should escape: it may be understood of Christ the mighty God, the Judge of quick and dead; see ( Jeremiah 50:34 ) .