3rd trumpet or shofar
Star called wormwood. A Meteorite, or by pollution or by both. Remember Egypt. Exodus 15:26-27, Exodus 10:21-23.
A third of the drinking waters turned bitter and many people died from the bitter water.
The trumpet referred to here was a shofar which is a ram's horn used by the Jews for religious purposes and for warfare.
Background Reading:
Revelation 8:10-11
The Third Trumpet
10 The third angel sounded his trumpet, and a great star, blazing like a torch, fell from the sky on a third of the rivers and on the springs of water— 11 the name of the star is Wormwood. A third of the waters turned bitter, and many people died from the waters that had become bitter.