PM Turnbull unveils tsunami memorial

Prime Minister Malcolm Turnbull says the lives of 26 Australians who died in the 2004 Boxing Day tsunami will be forever bound together by tragedy.

Speaking at the unveiling of a memorial for the Australian victims in Canberra, Mr Turnbull said it was a place where he hoped grief could give way to commemoration.

"They may be buried in different places, but their lives are forever bound through that one fateful moment," he said.

The survivors and those who lost loved ones had carried the burden of being the national memory of "this incredibly cruel and sad event".

"Now we have a place where we can reflect on these events."

The tsunami spread despair and destruction across 14 countries around the Indian Ocean, and left a death toll of more than 225,000.

Mr Turnbull also paid tribute to the nine defence force personnel who were killed in a helicopter crash on the Indonesian island of Nias during humanitarian efforts in the catastrophe's aftermath.

"We cannot speak of the tragedy of the tsunami without also speaking of those who responded with such courage and selflessness," he said.

"Today also reminds us just how dangerous this work can be."

Opposition Leader Bill Shorten said it was impossible for those who were not there to imagine the "incomprehensible terror" of the disaster.