The judgment over Capernaum is mentioned separately because its wickedness surpassed that of the other cities, but when Jesus says that Capernaum will be brought down to Hades (Matthew 11:23), he did not mean that every inhabitant of the city would be lost, but rather that the city itself would be destroyed, which is what happened when in the wars between the Romans and the Jews, Capernaum and the surrounding cities were completely ruined. Today it is hard to know their exact locations.
No, when Jesus says that Capernaum will be brought down to Hades (Matthew 11:23) he does not mean that every inhabitant of the city would be lost, but rather that the city itself would be destroyed. And this is exactly what happened: through the wars between the Romans and the Jews, Capernaum and the surrounding cities were completely ruined. Today it is even difficult to determine their precise locations.1
The judgment over Capernaum is mentioned separately because its wickedness generally far surpassed that of the other cities. Yet one must not read this as if all the inhabitants of Capernaum would go to hell. Jesus is proclaiming a great fall—that is, a severe judgment, a heavy punishment—which may include eternal punishment, but first of all refers to a devastating judgment on the city.2
23 And you, Capernaum, will you be exalted to heaven? You will be brought down to Hades. For if the mighty works done in you had been done in Sodom, it would have remained until this day.