Revelation 8:10-11 - The Third Trumpet
10 And the third angel sounded; and there fell from heaven a great star, that burned as a lamp; and it fell upon the third part of the rivers, and upon the fountains of waters. 11 And the name of the star is called Wormwood; and the third part of the waters became wormwood: and many men died of the waters, because they were made bitter.