When Hugh Hefner passed away in 2017, the public was understandably divided about how to mourn. On the one hand, Hugh was a human, and any person's passing is sad, no matter how old they are.

But on the other hand, Hefner did rile up certain groups during his lifetime, and he was quite controversial for his marriages, unconventional living arrangements, and much-younger wives and girlfriends.

He also made plenty of headlines for a range of reasons. One time he even attempted to solicit certain services from Jennifer Aniston. But Hugh's family thought pretty highly of the mogul, especially as his legacy continues to live on in various forms.

In fact, while none of his children have followed in Hugh's exact footsteps, his daughter did have a specific opinion of her dad's company. Hint: she later became its CEO.

Clearly, Hugh is widely missed by his friends, family, fans, and past girlfriends, and his wife at the time of his passing. But what ultimately caused his demise?

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When Hugh died, one cartoonist's animated drawing showed the Playboy Mansion as a party hotspot and mimicked 'deliveries' of certain little blue pills being dropped off by the truckload. The cartoon even suggested that Hugh had passed from decidedly unnatural causes.

And unfortunately for the Hefner family, there was plenty of speculation about why Hugh passed. To be clear, he was 91 at the time he passed away, so he had lived a long life. But there was some confusion over how he passed because his spokesperson originally cited "natural causes," noted Newsweek.

As it turned out, an examination later found that there were multiple factors that contributed to Hefner's death. For one thing, the death certificate listed cardiac arrest as the primary cause. But two other factors were listed as contributing to the mogul's state.

One was a blood infection, noted Newsweek, and another was an E. Coli infection.

Septicemia, which is bacteria in the blood, and E. Coli were listed as issues with Hugh's health before his passing. Essentially, an E. Coli infection led to sepsis, and though that didn't kill Hugh, it surely didn't mean he was healthy at the time of his passing.

Though he always kept outward appearances upbeat, AOL suggests that Hugh's conditions were "debilitating" near the end of his life. In addition to the blood issues and infections, Hugh also had a back problem that became incrementally worse over the years, said AOL.

It's a sad end to a long and illustrious Playboy history, but Hugh's legacy does live on with his children, and not just in terms of his brand. By all accounts, Hugh was a loving father to his kids, and they haven't forgotten him.

NEXT: How Much Are Hugh Hefner's Kids Worth Today?