Bruce Lee died from a cerebral edema due to hypersensitivity to aspirin, according to a coroners report, I don't think Bruce did smack and coke, might av done, but I doubt it cuz of the amount of pride he had for his physical abilities. Some ganja was found in his stomach, so some ppl did try to say the congestion of fluid was caused by a chemical reaction due to the weed, but this was later ruled bollox by the coroner.
But tis tru wat 007 sez, it'd be easier to overdose on water, cuz you'd get to point where ure so fucked you'd pass out for a couple of days, they did that experiment with a dog once, injected it with an unbelievable amount of pure THC, they were almost certain the dog was gonna die when it collapsed in to a deep sleep, but after 2 days of nothing but sleep, the dog woke up fine.