The conclusion of the Book of Mormon saga is simultaneously depressing and hopeful. This people that had been so favored by the Lord and just a few generations before had enjoyed the personal visit of the resurrected Christ followed by an era of peace that lasted more than 100 years, now descends into complete depravity. When society spirals down to a state where everyone "delights in bloodshed," the end cannot be far away. Nevertheless, there is a future, and we are the recipients of this marvelous record that Mormon and others preserved and Joseph Smith translated. It is a warning to us in our day, and there is the hope that we will heed its warning, repent, and avoid the same end the Nephites suffered.
Mormon makes this intriguing statement:
5 But, behold, the judgments of God will overtake the wicked; and it is by the wicked that the wicked are punished
There are cases in the scriptures where God seals the heavens so that there is famine, or sends natural calamities like earthquakes or storms. These kinds of events try the souls of men. But it is also true that the wicked prey upon the wicked. Righteous acts of kindness and charity obviously can't be "punishment" for anyone. So, we generally reap what we sow -- wickedness plagues the wicked. Unfortunately, rain falls on the righteous as well, and evil acts impact them as well.