It's both, accidental and purposeful. Mostly accidental, as drug dealers don't want to kill off their customers as it would be counter productive for business. When done purposeful, Fentanyl is cut into cocaine and MDMA and other drugs in very miniscule amounts (few hundred micrograms - the weight of a single grain of salt) because it's dirt cheap and a little goes a long long way in increasing the potency of the recreational drugs. When cut properly, it's more cost effective than it would be to increase the purity of the cocaine. Fentanyl is what killed Prince.
I hadn't realised this about Prince - thanks. And one has to wonder at the ability of the average UGL to adulterate powders to that degree of accuracy, surely?
A kilogram will produce a half a million doses. It's dirty bomb dangerous
Yikes!

So with this in mind (and I know it's a terribly ghoulish thing to speculate) one possible scenario of what happened could go something like:
> Rich is chilling with a few lines of "good sh1t" Monday night and getting his hair styled
> Accidentally ingests a couple grains worth of this stuff
> Sudden syncope
> Straight down and strikes head on tiled floor (causing sub-dural haematoma?)
> CPR until paramedics arrive
> Coma induced at hospital
So what's next? If it was a haematoma might surgery be indicated? Or if this Fentanyl sh1t is involved, perhaps the head-strike is a red herring and the drug actually stopped his heart?
This thread needs more wild speculation, spurious logic and broscience!