18 A third of mankind was killed by the three plagues of fire, smoke and sulfur that came out of their mouths.

Read Revelation 9:18 Using Other Translations

By these three was the third part of men killed, by the fire, and by the smoke, and by the brimstone, which issued out of their mouths.
By these three plagues a third of mankind was killed, by the fire and smoke and sulfur coming out of their mouths.
One-third of all the people on earth were killed by these three plagues—by the fire and smoke and burning sulfur that came from the mouths of the horses.