Before the hand up "free catch" rule on fourth down, a fast player could run past and hit the receiver from behind just as another player hit the receiver head on -- resulting in almost tearing the receiver apart.
Years ago, I saw that play happen; the fast player ran past and hit the receiver low and the other player hit the receiver high.
The ball was fumbled, the victim was carried off on a stretcher, abd the fair catch rule was soon adopted.
That's why we used to call punt coverage "Suicide Squad". Any player who had the guts to field a punt was essentially committing suicide.