Their closest friends and former classmates marked the solemn occasion with a candlelight vigil outside their home on La Sierra.
They lit candles and placed them at the garage of the house.
They also prayed for the two sisters who they describe as close and full of life.
Olivia was a Dilworth student while Veronica attended Reed.
Mourners say they were loved by students, teachers, but most of all they loved each other.
Best friend, Tasha Gowniak, expressed how "Veronica was like a mother figure. She gave me a few tongue lashings over the years. But, deep down inside she loved me and I loved her."
Reno Radaza, former classmate, echoed that "he still drives by their house every once in a while and wishes Veronica could help him when he's depressed."
And, Arron Wood, says "their Christmas ritual this year without the sisters was not the same."
The girls' mother was at the vigil but declined to talk on camera.
She told News Channel 8 it had been a difficult year, but planned on rebuilding the house.
She also wanted to thank all her daughters' friends for their continued support.