"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;
And the name of the
star is called
Wormwood: and the third part of
the waters become wormwood; and
many men died of the waters,
because they were made bitter.
Revelation 8:10-11

A large meteor(?), falls from heaven,
containing a poison that spreads into
the rivers and springs. There will be
no fresh water.

Of course, many will die from the
water. Wormwood means sorrow and
calamity.