Revelation 9:15

Then the four angels that were held in readiness for that hour and day and month and year, were let loose, to destroy a third of mankind.

Revelation 8:7

And the first angel blew his trumpet, and there followed hail and fire mingled with blood, and it fell upon the earth; and the third part of the earth was burned up, and the third part of the trees, and all the green grass.

Revelation 9:18

By these three plagues a third of mankind were killed; by the fire and the smoke and the brimstone which issued from their mouths.

Revelation 8:9

and a third part of the living creatures in the sea died, and the third part of the ships were destroyed.

Revelation 8:11-12

A third part of the waters became wormwood; and many men died of the waters, because they were made bitter.

Revelation 9:5

Yet they were not permitted to kill them, but only to torture them for five months. Their torture was like the torture of a scorpion, when it stings a man.

Revelation 9:10

And they have tails like scorpions, and stings, and their power to torture men five months was in their tails.

Treasury of Scripture Knowledge

Summary

And the four angels were loosed, which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men.

An hour

Bible References

An hour

Revelation 9:5
Yet they were not permitted to kill them, but only to torture them for five months. Their torture was like the torture of a scorpion, when it stings a man.

For to

Revelation 9:18
By these three plagues a third of mankind were killed; by the fire and the smoke and the brimstone which issued from their mouths.
Revelation 8:7
And the first angel blew his trumpet, and there followed hail and fire mingled with blood, and it fell upon the earth; and the third part of the earth was burned up, and the third part of the trees, and all the green grass.