8:10 And the third angel sounded, and a great star fell from heaven, burning like a torch, and it fell on a third of the rivers and on the springs of waters;

And the THIRD ANGEL sounded, and a GREAT STAR fell from heaven, burning like a torch,

The literal view of this is that this is something entering the earth's atmosphere from outside or above the clouds. Some scholars believe this may be a nuclear missile (like a torch) and use the next verse to authenticate the nuclear warhead. Whatever this GREAT STAR is, it is burning up in the atmosphere and pieces apparently are landing in rivers and other bodies of water. It is not clear why the surrounding land is not included in this verse.

The symbolic view is that there is a "high-level" purging of demonic forces in heaven. It is possible that what is visibly shown here during the THIRD TRUMPET, is also what the rejoicing is over in Revelation 12:12, where the down casting of the devil is in the past tense, "has come down". The fact that the devil, a fallen angel, is equated to a great star is supported by the fact that the seven angels of the seven churches are also refereed to as stars in Revelation 1:20.

and it fell on a THIRD of the rivers and on the SPRINGS of waters.

The literal view is that if it is a nuclear explosion, the residue radioactivity would run off in the rivers and seep into the ground water (springs). This may be what this is, however, ground seepage to cause springs to be radioactive is a longer process -- longer than the seven years of tribulation.

The symbolic view would say that fully a THIRD of the spirit side of this earth is affected. Recall that the serpent in Revelation 12:15 tries to flood out the woman (Christianity) with a great flood of water. That this is an evil tide affecting a third of the people is confirmed in Revelation 17:15. Note that this verse does not say that the THIRD dies ... it just fell on them. The consequences would be a populace "hell bent" on evil and crime. It will not be fun to live during this period.