Remembering Steve: Father's Day 2016 marks 10 years since death of the Crocodile Hunter

Ten years ago today, September 4 2006, the world was shocked to hear of the death of The Crocodile Hunter, Steve Irwin.

At 44-years-old, Irwin died after he was struck multiple times by a stingray barb while filming in waters off Queensland’s Port Douglas.

Australia was sent into mourning following his death, which Prime Minister John Howard described at the time as a “huge loss” and said Irwin was "the Australian many of us aspire to be".

When Steve Irwin died, his daughter Bindi was only eight and his son Robert was a tiny two-year-old.

This morning, which coincides with Father’s Day, now-eighteen Bindi Irwin shared a touching tribute to her father on Twitter.

“You’ll be my hero for my entire existence. I love you more than words can describe,” she wrote, alongside a photo of her as a baby with her proud father holding her up high.

Today Australia Zoo will host a Father’s Day event, however Bindi, Robert and their mother Terri are not expected to attend.

Australia Zoo has confirmed the family plan to keep their movements private today.

"I have no fear of losing my life - if I have to save a koala or a crocodile or a kangaroo or a snake, mate, I will save it," - Steve Irwin.

Bob Irwin has also opted not to share how he will mark the tenth anniversary of his son’s tragic death.

This week Bob Irwin shared a touching letter written by Crocodile Hunter to his parents.

The legendary conservationist penned the memo to Lyn and Bob Irwin when he was just 32 years old.

Bob Irwin recently discovered the unopened letter after it fell from a book while he was researching information for his memoir, The Last Crocodile Hunter: A Father and Son Legacy.

The heart-breaking piece outlined Steve's gratitude for his upbringing and revealed a man who had just started to find joy and understand his purpose in life.

“Probably one of the most unfortunate things in a bloke’s life is that it takes over 30 years to realise how essential you have been to build my character, my ethics and, most importantly, my HAPPINESS,” Steve wrote.

"Yeah, I'm a thrill seeker, but crikey, education's the most important thing," - Steve Irwin.

“At 32, I am finally starting to figure it out. In good times and in bad, you were there.

"Your strength and endurance to raise me will not go unrewarded. My love for you is my strength!

“For the rest of my life I will reflect on the unbelievably GREAT times we’ve shared and will continue to share.

"You’re my best friends!”

Earlier this week John Stainton, who was with Irwin when he died, shared the story of how he watched him pass away in the bottom of the boat.

Ten years on he said he remembered his mate, whose generosity and courage still amaze him.

Stainton, the Crocodile Hunter's producer, has so many surreal memories of Irwin.

These moments include the day the late Irwin saved him - with what felt like superhuman strength - from a charging Komodo dragon that wanted their chicken lunch.

And the moment Irwin put his body between Stainton and an angry, rearing Egyptian cobra, its fangs poised and ready to deliver a deadly injection of venom.

Then there was Irwin's reaction to the Boxing Day tsunami, when he ordered all of his wildlife hospital vets to Indonesia to treat the shredded feet of elephants being used to pull bodies from the sea of rubble.

But all those memories pale beside one Stainton desperately wishes he didn't have.

"It's something that I'll never forget, no matter if it's 20 years from now," Irwin's long-time friend, sometimes cameraman, and manager told the ABC last week.

"It's really hard to talk about. It was just a horrific situation. You don't believe it, you have to pinch yourself that something like that is happening in front of you."

In the years since Steve Irwin’s death, his wife and children have taken up where he left off, as loud voices for the protection of Australian wildlife and the habitats that sustain them.

Bindi, now 18, says she's proud of that work and being able to build on her dad's legacy.

Robert, now 12 and looking like a carbon copy of his dad, is also along to help catch crocs for scientific study.