Answer:
Step-by-step explanation:
It is written by a man who survived the Nazi death camps. He (in this novel) is a young boy who is taken to the death camps with his father (who did not survive what the Nazis were determined to do -- kill all Jews everywhere).
What you are reading is saying exactly what the words imply. One by one, people were marched to a ditch. They were unarmed. It included men, women and children, all unarmed.
When the got to the trench (which they themselves had dug -- it doesn't tell you that here), they were shot or their throats were cut. Death sometimes didn't come quickly.
Meanwhile, babies were thrown in the air and shot by machine gunners. It was a sport to the Nazis.
I hope that's clear enough. This material is hard to read and hard to write about. Take it seriously. It happened, just as Wisel recorded it.