Irwin (who, as any reader of Boundary probably guessed, was being referenced by my Aussie pilot Bruce Irwin) died from being stung in the chest by a stingray. The barb penetrated his heart, probably killing him instantly. (For those who don't know, an adult stingray's sting can be six to eight inches long, are venomous, and are serrated like steak knives with backward-pointing, harpoonlike barbs.
Given his lifestyle, I doubt that anyone is surprised by the idea that he was killed by some dangerous animal. What is surprising is that apparently Steve wasn't even wrangling with the stingray. According to the witnesses, the ray just stung him out of the blue. This is EXTREMELY rare and the kind of thing that all the skill and training in the world can't save you from.
I had immense respect and admiration for Mr. Irwin. It was clear that he loved the animals he worked with, and he treated them -- for all his cheerful showmanship -- with care and respect. He always examined the proper techniques for handling any creature he encountered, and taught a generation of kids that even creatures with huge teeth, poison, and mean attitudes were "gorgeous!" animals worthy of admiration and even love and protection.
So here's to you, Steve! Crikey!