The greatest single loss of life ever sustained by the Royal New Zealand Navy is being commemorated in Wellington.
On 19 December 1941, the Leander-class light cruiser HMS Neptune sank in the Mediterranean Sea off Libya after hitting uncharted enemy mines.
Of the 757 men who lost their lives in the sinking, 150 of them were New Zealand sailors.
Only one man from the entire crew survived.
The HMS Neptune sinking is this country's worst naval tragedy.
The navy said while the crew of HMS Neptune fought to save the ship, there would have been many acts of gallantry and heroism that went unrecorded.
Tonight's public commemoration service at Pukeahu War Memorial - starting at 8.30pm - was expected to be attended by Governor-General Dame Patsy Reddy and Defence Force chiefs.
The two-hour service was scheduled to include an audiovisual presentation projected onto the front of the National War Memorial, telling the story of the ship.
On a visit to New Zealand in 1991, Norman Walton - the only survivor - spoke of being on a liferaft with other men for more than a week, and as they died, he was left alone.
He said there were five or six left and on the fourth day the skipper died. And then the others died, one by one.
"The awful feeling of being hopeless, couldn't do anything, just having to watch them was the worst part."
After he was picked up he was taken to a hospital in Tripoli.
"I was blind at first and was for a couple of days, and I had a gash on my leg."
Mr Walton said he had been asked many times how he was able to survive, and it was a question he asked himself many times.
"Why me? I keep making excuses - I was a very fit kid and all that sort of thing, but it bothers me thinking why it had to be me. The good Lord has his idea and has your number up there, when you have got to go."
This year is the 75th anniversary of the foundation of the Royal New Zealand Navy and commemorative events and activities over the past year have been collectively named Operation Neptune, in honour of the ship and the men who lost their lives.