Mormon finishes the successful expulsion of the Lamanites by turning to the city of Ammonihah. He first notes that “every living soul of the Ammonihahites was destroyed.” Of course, that is hyperbole. Typically, some people survive such invasions, and if there was no one else, the returned captives survived. Mormon’s point is not pure and accurate history, however. It is theologically important to note that they were all destroyed, because the best shows the fulfillment of the prophecy. We are to remember that the righteous of Ammonihah had either been killed by the Ammonihahites or had fled to Sidom.
The picture of the heaped dead is meant to invoke destruction, and Mormon specifically says that “in one day it was left desolate.” Mormon places an extra meaning on the word desolate. He will use that word more and more in conjunction with both the lands, and the people of Jared. Mormon is setting up the comparison between desolation for Ammonihahite wickedness and the end of the Jaredites in desolation for their wickedness.
Notice how Mormon emphasizes the idea of desolation. “And it was called Desolation of Nehors.” “Their lands remained desolate.” It is not a coincidence that the land northward, the land that Mormon associates with the Jaredites, is called the Land Desolation, in dramatic counterpoint to the Nephite land to the south, the Land Bountiful. These are names with a purpose.