Scriptures

Alma 2
Careful reading reveals the scope of this event.  The Nephites were a numerous people now.  The Lamanites were as the sands of the sea.  Even women and children were killed.  This was a horrific calamity.

Alma 3
The Almlicites marked themselves just as we all bring on our own condemnation. See verse 19.

Alma 4:19
Pure testimony is sometimes the only solution.