Audrina Patridge's teenage niece has died aged just 15 as tributes pour in for "sweet Sadie".
The Hills star's family have been left heartbroken by their loss, with the youngster's mum Casey Loza announcing the news in a heartbreaking post on Instagram.
"Writing this was the hardest thing I ever have had to do," she penned to her 80,000 followers. "Sadie Raine Loza has left this Earth for the heavens."
She added: "Transformation is a better word than death. Her story will save countless lives, her memory will never be forgotten. Rest In Peace you brilliant starseed.
"You’re with your creator. We will miss you dearly. I love you."
Teen Mom star Taylor Selfridge was amongst the first to share their condolences, writing: "I’m so sorry Casey. Sending my love & prayers to you and your family."
Audrina commented on her sister's post, leaving two love heart and two crying face emojis.
Penning a long tribute moments later, she wrote on her own page: "My heart hurts to even write this. My beautiful niece is now in heaven.
"I know Its not goodbye forever, but it is the hardest to say goodbye for now.
"We will miss you and cherish every single moment we had with you. Rest in peace Say Say!! We love you forever & ever!"
"I am so deeply sorry," replied one concerned follower.
Another added: "Oh my god, Casey. I am so sorry! That’s absolutely heartbreaking. I feel like I’ve watched her grow up into such a beautiful young lady.
"I’m so so sorry for your loss, I can’t even begin to imagine the pain you’re going through right now."
While someone else wrote: "Casey this news is unimaginable and I am in pieces hearing this is what your family is facing.
"If words could bring comfort I’d write to you forever, im so sorry…. Sleep in peace sweet Sadie girl."
Fans of The Hills know Audrina's sister Casey following her appearances on the hit-MTV show alongside her famous sibling, who now boasts almost 2million followers on social media.
Sadie had only just celebrated her 15th birthday, with her mum sharing a sweet video of the teenager blowing out her candles earlier this month.
She is one of two children Casey shares with her motorcross rider husband Kyle Loza - they also have a 12-year-old son, Sam.
Casey wrote at the time: "I cant believe you're 15. it feels like the years flew by and we still have so many more adventures to go on! aliens in sedona, portals, learning to drive in the desert hahah.
"I love you so much my little clone. youre so beautiful, kind, smart and funny!! that dryyy af british humor tho.
"Im so proud to be your mom and i cannot wait to see the insane ancient civilization architecture you’re going to construct someday. i love you so so much my sadie raine."
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