News filtered through on Monday morning our very own ironman champion from Thirroul, Dean Mercer, had passed away on the Gold Coast.

It’s believed the loving husband and devoted father had suffered a cardiac arrest behind the wheel.

The outpouring around the country was instantaneous, such was the impact of Mercer who was renowned for his gutsy performances.

Ironman Ky Hurst was among many to lead tributes to Mercer, with Hurst writing on Instagram: "Heavy heart today losing one of the greatest athletes of all time. Dean was someone I raced most of my career. I looked up to him as an athlete and a friend. My love goes out to the Mercer family."

Through social media, others joined the chorus, paying tribute to Mercer’s enormous legacy.

A family friend of the McKeon family swimming dynasty, Olympic swimmer David McKeon said “Tonight my Pop (Rick McKeon) will be having a cold beer with the Australian Legend up there. RIP Dean Mercer.”

Champion cyclist Robbie McEwen tweeted: “Devastated to hear Dean Mercer, surf lifesaving legend & absolute top bloke passed away suddenly this morning. Thoughts are with his family.

RIP Stumpy Evan Thomas, Bulli

Rest in peace Dean. Sending our condolences to family and friends. Our prayers are with you at this sad time. Bennie family, Balgownie

A true legend and inspiration to so many gone to soon Anthony Newbery, Bridgeman Downs

Dean was my training partner with Ron McKeon in the late 90's. He was the inspiration for my swimming career which pushed me onto the international scene and a Commonwealth Games Gold medal. Your lessons in motivation and pure determination shaped me into the international athlete I was and the person I am today. Nearly 6hrs on from learning of his passing; I'm still in shock however so thankful of the friendship and the lessons learnt from one of the greatest athletes of our time. Condolences to your Reen, the boys and your extended family. I'll miss seeing your friendly face at Aussies next year. Rest in peace. You are a true legend! Jason Cram, Woonona

I remember when Darren and Dean were doing laps at Austi pool while John and the Austinmer Otters were having their winter swims. That would have been 35 years ago I guess. My condolences to the family at this tragic time. Alyn Vincent, Thirroul

Christchurch oh my god so sad Shirlette Williams, Christchurch 

I grew up seeing the Mercer boys on the back (and front!) page of the Mercury every weekend in summer. They were part of the Wollongong furniture. I remember when Dean came of age, eclipsing Darren, it was history in the making. Dean was the quintessential local hero and will be always. My condolences to all Dean's family and friends. Claudia, North Wollongong

To the Mercer Family, Deans wife & boys, thinking of you all at this very sad difficult time, how quickly someone can be taken away from us. Amanda, Corrimal

Rip dean your were a great champion and will be sadly missed my sincere condolences to his family fly high mate x Dannielle rath, Port Kembla

You will be missed Dean Thinking of your family gone to soon Judeth and Michael Mcdon, Woonona

My deep condolences to Deans family. We have all lost an Illawarra icon George Pastrovic, Mt Warrigal

The 80's and 90's were all about Dean and Darren and Crowy and Clayto. Such incredible competitors. And as a proud Illawarrian the Iron Man series was a must-watch and made all that much better with a Wollongong bloke on the podium. Vale Dean. Far too young to go. A tough and tenacious player leaving behind an incredible legacy. His kids should be proud and grow up knowing what a great sportsman he was. My thoughts go to the family. Rest in Peace, Dean Ted Hanson, Wollongong

So sorry rip gone too young Renee Johnstone, Woonona

Everyone in Thirroul knew Dean as our golden boy of the ocean ,he was a beautiful man inside and out . . He was the epitome of being healthy ,active and happy . Would always take the time to say hello to everyone and never without a smile . Broken hearted for his wife , boys , brother Darren , sister Kylie and his mum and dad . Sending love and light to you all on a life cut way too short Bianca Kent, Thirroul

so sorry rip gone to young renee johnstone, woonona

Everyone in thirroul knew dean as our golden boy of the ocean ,he was a beautiful man inside and out . . He was the epitome of being healthy ,active and happy . Would always take the time to say hello to everyone and never without a smile . Broken hearted for his wife , boys , brother Darren , sister Kylie and his mum and dad . Sending love and light to you all on a life cut way too short. Bianca Kent, Thirroul

You were an inspiration,gentleman and true champion. RIP Deano Mark Wallace, Helensburgh

An Absolute Champion Of The Sport, Loving Father Who Did Anything for Anyone, Was One Never To Give Up In The Sport He Loved, An Illawarra Product Who Will Be Sadly Missed By All Vale Dean Mercer R.I.P Mark Osborn, Mount Warrigal