When the end came for television's beloved "Crocodile Hunter," it was in an encounter with a stingray and its venomous tail barb.

Perhaps it wasn't surprising. Steve Irwin died doing what he loved best, getting too close to one of the dangerous animals he dedicated his life to protecting with an irrepressible, effervescent personality that propelled him to global fame.

The 44-year-old Irwin's heart was pierced by the serrated, poisonous spine of a stingray as he swam with the creature Monday while shooting a new TV show on the Great Barrier Reef, his manager and producer John Stainton said.

Marine experts called the death a freak accident. They said rays reflexively deploy a sharp spine in their tails when frightened, but the venom coating the barb usually just causes a very painful sting for humans.

"It was extraordinarily bad luck," said Shaun Collin, a University of Queensland marine neuroscientist. "It's not easy to get spined by a stingray, and to be killed by one is very rare."

News of Irwin's death reverberated around the world, where he won popularity with millions as the man who regularly leaped on the back of huge crocodiles and grabbed deadly snakes by the tail.

"Crikey!" was his catch phrase, repeated whenever there was a close call - or just about any other event - during his TV programs, delivered with a broad Australian twang, mile-a-minute delivery and big arm gestures.

"I am shocked and distressed at Steve Irwin's sudden, untimely and freakish death," Australian Prime Minister John Howard said. "It's a huge loss to Australia."

Conservationists said all the world would feel the loss of Irwin, who turned a childhood love of snakes and lizards and knowledge learned at his parents' side into a message of wildlife preservation that reached a television audience that reportedly exceeded 200 million.

"He was probably one of the most knowledgeable reptile people in the entire world," Jack Hanna, director emeritus of the Columbus Zoo and Aquarium in Ohio, told ABC's "Good Morning America."

In high-energy programs from Africa, the Americas and Asia, but especially his beloved Australia, Irwin - dressed always in khaki shorts, shirt and heavy boots - crept up on lions, chased and was chased by komodo dragons, and went eye-to-eye with poisonous snakes.

Often, his trademark big finish was to hunt down one of the huge saltwater crocodiles that inhabit the rivers and beaches of the Outback in Australia's tropical north, leap onto its back, grabbing its jaws with his bare hands, then tying the animal's mouth with rope.

He was a committed conservationist, running a wildlife park for crocodiles and other Australian fauna, including kangaroos, koalas and possums, and using some of his TV wealth to buy tracts of land for use as natural habitat.

Irwin was in the water at Batt Reef, off the Australian resort town of Port Douglas about 60 miles north of Cairns, shooting a series called "Ocean's Deadliest" when he swam too close the stingray, Stainton told reporters.

"He came on top of the stingray and the stingray's barb went up and into his chest and put a hole into his heart," said Stainton, who was on board Irwin's boat, Croc One, at the time.

Crew members administered CPR and rushed to rendezvous with a rescue helicopter that flew to nearby Low Isle, but Irwin was pronounced dead when the paramedics arrived, Stainton said.

"The world has lost a great wildlife icon, a passionate conservationist and one of the proudest dads on the planet," Stainton said. "He died doing what he loved best and left this world in a happy and peaceful state of mind. He would have said, 'Crocs Rule!"'

Irwin's image was dented a bit in 2004 when he held his month-old son in one arm while feeding large crocodiles inside a zoo pen, touching off a public outcry. He argued there was no danger to his son, and authorities declined to charge him with violating safety regulations.

Later that year, he was accused of getting too close to penguins, a seal and humpback whales in Antarctica while making a documentary. An Australian Environment Department investigation recommended no action be taken against him.

Irwin was born Feb. 22, 1962, in the southern city of Melbourne to a plumber father and a nurse mother, who decided a few years later to chase a shared dream of becoming involved in animal preservation.

They moved to the Sunshine Coast in tropical Queensland state and opened a reptile and wildlife preserve at Beerwah in 1970. Irwin said in a recent interview that he was in his element.

He was given a 12-foot scrub python for his sixth birthday and regularly went on capturing excursions with his father in the bushland around the park. He was catching crocodiles by age 9, and in his 20s worked for the Queensland state government as a trapper who removed crocodiles from populated areas.

Irwin's father, Bob, said his son had an innate affinity with animals from an early age, a sense Irwin later described as "a gift." Irwin said he learned about wildlife working with his parents rather than in school.

In 1991, Irwin took over the park, Australia Zoo, when his parents retired and began building a reputation as a showman during daily crocodile feeding shows.

He met and married Terri Raines, of Eugene, Ore., who came to the park as a tourist, that year. They invited a television crew to join them on their camping honeymoon on Australia's far northern tip.

The resulting show became the first "Crocodile Hunter," was picked up by the Discovery Channel the following year, and the resulting series became an international hit.

Irwin was more famous in the United States than at home, where he typified a knockabout, rascally character that Australians call a "larrikin" and who many people worried painted a stereotypical picture of Australians as brash and uncouth.

Irwin loved Australia and its people, though, describing it as the greatest land on Earth.

By 2002 he had starred in his own movie, "The Crocodile Hunter: Collision Course," and appeared in the Eddie Murphy movie "Dr. Dolittle 2." Australia Zoo had become a major attraction and the Australian government enlisted him as the star of international tourist campaigns.

When President Bush visited Australia in 2003, Irwin was among the guests hand-picked by Howard to attend a ceremonial barbecue - and he turned up in his khakis.

At Australia Zoo in Beerwah, flowers and cards were dropped at the entrance Monday as news of Irwin's death spread. "Steve, from all God's creatures, thank you. Rest in peace," said a card with a bouquet of native flowers.

Irwin is survived by his wife Terri, daughter Bindi Sue, 8, and son Bob, who will turn 3 in December.