WoW! What a strange and unusual way to go!
Just after 11am, Irwin's heart was punctured by a bull ray's barb as he and a cameraman snorkelled in the shallows off Batt Reef. By noon he had been pronounced dead.
The water was alive with stingrays, some of them 2m across. Irwin singled out one of the creatures and dived down, possibly intending to latch on, the sort of derring-do that had earned him a world-wide audience of hundreds of millions and made him the most famous Australian alive.
The cameraman realised that Irwin was in trouble only when his blood began to stain the water.
Chances are Irwin, 44, was already beyond help. The stingray's barb had knifed through his chest, piercing his heart.
A distraught Mr Stainton said later Irwin had probably died instantly, so catastrophic was the injury.
"I don't think he would have felt any pain," Mr Stainton said. "It was a very unfortunate accident the way it happened. He came over the top of the ray and the barb came up."
Irwin was taken by dinghy to nearby Low Isles, an island nature reserve, where desperate attempts were made to resuscitate him. An emergency helicopter from Cairns reached the scene just after noon.
"It became clear fairly soon that he had non-survivable injuries," said Ed O'Loughlin, the Emergency Management Queensland doctor who tended Irwin. "He had a penetrating injury to the left front of his chest. He had lost his pulse and wasn't breathing."