Mormon 6

12 And we also beheld the ten thousand of my people who were led by my son Moroni.
13 And behold, the ten thousand of Gidgiddonah had fallen, and he also in the midst.
14 And Lamah had fallen with his ten thousand; and Gilgal had fallen with his ten thousand; and Limhah had fallen with his ten thousand; and Jeneum had fallen with his ten thousand; and Cumenihah, and Moronihah, and Antionum, and Shiblom, and Shem, and Josh, had fallen with their ten thousand each.
15 And it came to pass that there were ten more who did fall by the sword, with their ten thousand each; yea, even all my people, save it were those twenty and four who were with me, and also a few who had escaped into the south countries, and a few who had deserted over unto the Lamanites, had fallen; and their flesh, and bones, and blood lay upon the face of the earth, being left by the hands of those who slew them to molder upon the land, and to crumble and to return to their mother earth.
16 And my soul was rent with anguish, because of the slain of my people, and I cried:
17 O ye fair ones, how could ye have departed from the ways of the Lord! O ye fair ones, how could ye have rejected that Jesus, who stood with open arms to receive you!

This would be so depressing. I would have had the same reaction. How horrid it would be to have to kill your brother because he was coming after you. It would be so terrible. And so sad.