What is the meaning of the story at the end of the book of Judges Chapter 19 in the Bible?

At the end of Judges Chapter 19 in the Old Testament after taking in a traveling Levite, the host offers his virgin daughter and his guest's concubine to a mob of perverts (who want to have sex with his guest). The mob refuses the daughter, but accepts the concubine and they "abuse (rape) her all night." The next morning she crawls back to the doorstep. The Levite puts her body on an *** and takes it home. Then he chops the body up into twelve pieces and sends them to each of the twelve tribes of Israel. No one ever asks God for any help in the story so I guess it's ok for people to gang rape a woman to death and then desecrate her body and God will sit there and watch but if children dare make fun of an old man He will send a bear to kill then (2 Kings Chapter 2 verse 24). What important moral values does God impart on humanity through the story of the concubine?