Steve Irwin's dying young is quite sad. With that personality, he would have made a great 'old geezer'.

It was mentioned above that rays are usually at the ocean bottom. That is because they have no air bladder to adjust buoyancy, as do fish. When a shark or ray stops swimming, if starts to sink.

For what it's worth, the ray has no brain as we know it. Just a nerve center. Sharks and rays are extremely primitive animals when you compare them to the normal 'boney fish'. Their relatives go back on Earth (in water, actually) about 1/2 billion years. Almost 'living fossils'. They have no ability to think, only to react to stimuli. The sting ray did not intend to kill, it just reacted.