The story I heard is that they had finished filming for 'dangers of the deep' or whatever it was to be called, and he and a camera man went looking for small animals for his daughters show..... Either way, all speculation at this point.....
Quote

"He came over the top of a stingray that was buried in the sand, and the barb came up and hit him in the chest," said Stainton.
http://www.kltv.com/Global/story.asp?S=5362163


Mark Heller
"Well - I oughta....." -Jackie Gleason