Hefner was the most prolific baby killer in history. He is responsible for the premature death of millions and millions of potential little boys and girls around the world. Domestic mothers facing the "missing sock crisis" had but one man to look at for the answer to why there was an odd number of tube socks coming out of the laundry (it wasn't the dryer's fault). Thanks to Hef's mansion, the words "grotto" and "debauchery" referenced each other in the thesaurus.
This was in the cards for some time now, and if I recall, Hefner, himself, said not too long ago that, "It won't be long, now...". He knew it was coming, and I guess at 91 years old you can't really say he "died unexpectedly". At that age, you "wake up unexpectedly". The man changed an entire culture. Enjoy your 72 girlfriends on the other side, Hef.