Revelation 9:18
One third of mankind was killed by these three plagues --- the fire, the smoke and the sulphur, which proceeded out of the horses' mouths.
Revelation 9:15
And the four angels who had been ready for this hour and day and month and year were [now] released to kill one third of mankind.
Revelation 9:17
And this is how the horses and their riders looked in the vision: They had on their chests fire[-red], [smoke-]blue and sulphur[-yellow] armor plate, and the horses' heads were like lions' heads. And fire, smoke and sulphur proceeded out of their mouths.
Treasury of Scripture Knowledge
Summary
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.
The third
Bible References
The third
Revelation 9:15
And the four angels who had been ready for this hour and day and month and year were [now] released to kill one third of mankind.