Former Wallabies lock Dan Vickerman has passed away suddenly at the age of 37 leaving the rugby world in a state of shock, the Australian Rugby Union said Sunday.
The South African-born lock, who played 63 Tests for the Wallabies up until 2011, passed away at his family home in Sydney late Saturday, the ARU said in a statement.
Vickerman leaves behind wife Sarah and two sons. Authorities have yet to comment on the cause of death.
"The rugby world is in shock today after news of the tragic passing of Dan Vickerman," ARU chief executive Bill Pulver said.
"Dan was an uncompromising competitor who forged a wonderful international rugby career despite a number of injury setbacks along the way.
"He was an enforcer on the field and a much-loved character off the field. He cared deeply about the game and the players, helping players transition into life after rugby in his role with (the players association) RUPA following his retirement.
"Our thoughts and prayers are with Dan's family at this extremely difficult time."
Vickerman's death has rocked the rugby world. "The shockwaves of his tragic passing will be felt right across our rugby community," Waratahs CEO Andrew Hore said in a statement.
RUPA CEO Ross Xenos said Vickerman was "deeply respected by his peers."
"On behalf of all players, we extend our deepest sympathies to Dan´s young family at this difficult time. We are truly shocked and united in our despair," Xenos said.
"Dan was universally respected by his peers and the rugby community during and beyond his playing days. Since retiring, he was very generous in giving back to the game through coaching and voluntary roles supporting players´ off-field development."
"We encourage all players who are affected by today's terribly sad news to support and be there for each other and to contact RUPA if they would like to talk."
Vickerman made his final Test appearance in the 2011 World Cup semi-final against New Zealand in Auckland.
Born in Cape Town, Vickerman moved to Australia with his family as a 21-year-old when he linked with the Brumbies and made his Super Rugby debut in the 2001 season.
In June 2002 made his Test debut in a 31-25 Wallabies victory over France in Sydney.
Following three seasons with the Brumbies, Vickerman was signed by the Waratahs in 2004 and played five seasons with them.
After playing in his second Rugby World Cup in 2007, he withdrew from international rugby for three years to study in England and earned a degree in Land Economics from Cambridge University.
While in England he played in two Varsity matches and also had a short stint with the Northampton Saints in the 2009-10 season.
The towering backrower returned to Australia to continue his career with the Waratahs and Wallabies, earning a place in the Wallabies 2011 Rugby World Cup squad.
He was forced to prematurely retire in 2012 due to persistent problems with stress fractures in his right leg.
Upon his retirement Vickerman worked in the real estate and development industry and was helping at Sydney University Rugby club until last year.