Revelation 8:8
King James Version
And the second angel sounded, and as it were a great mountain burning with fire was cast into the sea: and the third part of the sea became blood;
Revelation 8:8 in context
And the seven angels which had the seven trumpets prepared themselves to sound.
The first angel sounded, and there followed hail and fire mingled with blood, and they were cast upon the earth: and the third part of trees was burnt up, and all green grass was burnt up.
And the second angel sounded, and as it were a great mountain burning with fire was cast into the sea: and the third part of the sea became blood;
And the third part of the creatures which were in the sea, and had life, died; and the third part of the ships were destroyed.
And the third angel sounded, and there fell a great star from heaven, burning as it were a lamp, and it fell upon the third part of the rivers, and upon the fountains of waters;