Translation
Because of this,
her plagues will arrive in a single day, i.e. death, mourning and famine, and she will be consumed with fire, for mighty is the LORD
GOD
who judges her.
Paraphrase
Because of her proud attitude, all her suffering will come upon her all at one time, i.e. death and mourning and famine, and she will be destroyed with the kind of punishment that leaves nothing behind, for mighty is THE SUPREME RULER, THE CREATOR AND OWNER OF ALL THINGS who judges her.