Amelia,
Down through the milleniums, humans have suffered the judgment of vessel death and complete death for those involved in judgments. Adam and Eve are a prime example and those who died in the flood are another.
Adam and Eve aged to death, but were under judgment of wrath. God simply let them age to death so that they could see what they had lost over the period of time they lived and so they could view the badness associated with their rebellion.
This natural death that occurs is because since the time that sin entered the fleshly creation, all have died off the planet in successive generations in keeping with God's altered plan. Even those of the pre flood era eventually passed over before a thousand years would be marked in a natural aging of the vessel and mortal death occurred.
Truthseeker