The 19-year-old from Burnaby, B.C., was on what was supposed to be a fun long weekend trip.
He was walking around Whistler village with friends, but became separated from them in the early hours of May 17 when he went into a 7-11 to buy a bag of chips.
As he left the convenience store, he was swarmed by up to 10 teenagers, and stabbed multiple times, said police. Three 17-year olds and one 18-year old, Arvin Golic, have been charged with manslaughter.
"This could have been anybody's child," said his tearful mother, Clara Gordic.
"Luka just went up there for fun, the way it's supposed to be ... They took his life away, for no reason."
Now, his family is hoping their loss will trigger tighter controls on knives, and tougher treatment for young offenders, through their #JusticeforLuka campaign.
"Hopefully we are going to be able to do something so that no parents again cry like we do," said his father, Mitch Gordic.
"We have to do something."