And the LORD was sorry that he had made man on the earth, and it grieved him to his heart.
All Commentaries on Genesis 6:6 Go To Genesis 6
Augustine of Hippo
AD 430
When God announces the death of all animals on the earth and in the air, the intention is to declare the magnitude of the coming disaster. There is no question here of punishing with death irrational animals as though they were guilty of sin.