How are they slain?

Isaiah 22:2 Thou that art full of stirs, a tumultuous city, a joyous city: thy slain men are not slain with the sword, nor dead in battle.

Is it like the following?

II Kings 19:35 And it came to pass that night, that the angel of the LORD went out, and smote in the camp of the Assyrians an hundred fourscore and five thousand: and when they arose early in the morning, behold, they were all dead corpses.