The stabbing of a New Zealand teenager who was walking on a quiet street with his older brother was sparked by an argument over a hat.
Maaka Hakiwai, 17, was fatally stabbed at Kings Park, 19km northwest of the Melbourne CBD, about 2.30pm local time on Saturday.
Maaka's brother, Nate, 18, was also stabbed and was taken to the Alfred Hospital in a critical condition.
The boys had been walking down a quiet street when a "carload of five thugs" pulled up beside them.
"Two boys jumped out of the car and asked Nate for his hat. Both boys said no and a fight broke out," a family friend told Daily Mail Australia.
Nate reportedly woke up on Monday night to the news his "best friend" had died.
"He cried to Karli, his mum, and said 'my best friend is gone' because the boys did everything together," Maaka's grandmother Yvonne Stirling told 7News.
Australian channel Nine News showed images of the blood-soaked footpath where the teens were attacked.
The devastated family of six had moved from the Gold Coast weeks earlier. They plan to fly Maaka's body home to New Zealand for the funeral.
They said they can't believe the senseless murder could be the result of something as trivial as a hat.
Karli is so disturbed by the "evil" incident she reportedly no longer wants to move to Melbourne.
The grieving mother-of-four posted a tribute to her two boys on her Facebook page, sharing an old photo of the "inseparable" teenagers.
"They did everything together, born less than a year apart. The boys were inseparable and loved by all who knew them.
"Both boys had immense love for their family, were devoted brothers and protectors of their two younger sisters," the couple said.
"Maaka our baby boy, pure evil has taken you from us at 17 years young. Your brother and best mate Nate continues to fight in hospital.
"We love you our son, brother, grandson, nephew & our dear friend. Fly high baby boy we love you more than words can express."
Maaka had been working as a concreter in his new city. He played rugby league and has been described as a "great mate with a big heart" by friends.
A friend of the family set up a GoFundMe appeal for the boys' parents Karli and Stirling Hakiwai.
The fund had raised more than $44,000 since it was set up yesterday.
"Pure evil presented itself when they boys were attacked while walking down their home street in Melbourne," the woman who set up the page said.
"Maaka was taken from our lives. Nate was able to fight through and is thankfully still with us, although still in hospital in a stable but critical condition.
"Stirling and Karli are experiencing unimaginable pain as they grieve this terrible tragedy."
No arrests have been made, and police haven't revealed whether they've got any suspects, but the family are holding out hope the attacker will be caught soon.
"I hope they realise how broken we are as a family, and I hope their family feels the same way when they are put in jail," the boys' grandmother said.