What happened when the third trumpet blew (Rev 8)?

A star named Wormwood falls to earth on 1/3 of the rivers and springs, and many died from the bitter water

And the third angel sounded, and there fell a great star from, 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 became wormwood; and many men died of the waters, because they were made bitter. Revelation 8:10-11