Why are we acting all shocked that folks on the skateboarding internet message board are wanting to know how one of the largest and most vocal celebrities in the industry suddenly died with no mention of cause of death being released. Of course we want to know. Just like we want to know how other celebrities died. What is the first question you think of when you hear about someone famous' unexpected death... "How did it happen?"
It is completely natural to ask and not, in my opinion, disrespectful to speculate, especially on a platform that more or less exists for rumor. It would be disrespectful to perpetually bring it up to Phelps' family and friends. If they don't want to talk about it, that is their right and we shouldn't bother them. But to act like it is somehow supremely forbidden to talk about this is moronic.
Phelps mysterious death, and it is only mysterious because they haven't released any info on it, is probably the biggest news in skating this year, and this year has been chock full of skate news. Frankly, the defensiveness of everybody towards inquiries makes it all the more fascinating.
All that being said, unless I hear otherwise, it's obviously drugs.