We've gone over this before, ad nauseum, but maybe you were not present?
Paul, who knew the Law better than you and I, and who spoke the language, states in his letter to the Corinthians (I Corinthians 15:21).
For since by man came death, by man also the resurrection of the dead.
So the view of an extremely learned Jewish scholar, a Pharissee of the Pharissees until he became a Christian, is that the book of Genesis indicates that Adam's sin brought death into the world.
Now, as I already alluded to, there are other theological views on the matter, and you are welcome to discuss them, but if we are going to discuss YEC views, certainly this is one of the primary beliefs and interpretations of how death came into the world for "Bible-believing Christians."
There are some Bible believers that think this could refer to man alone, but both groups accept the Fall.