Audrina Patridge, who rose to prominence in The Hills for six seasons between 2006 and 2010, recently revealed that her 15-year-old niece, Sadie Loza, passed away.

The adolescent girl was born in 2008 to Casey Loza, Audrina’s sister, and Aaron Hershman, whom Casey previously dated.

Audrina paid tribute to her late niece on Instagram. “I know it’s not goodbye forever, but it is the hardest to say goodbye for now. We will miss you and treasure every moment we had with you. Rest in peace!! We will love you forever and ever!” she wrote, adding that it “hurts even to write this.”

Brody Jenner, Rachel Bilson, Paris Hilton, Ashley Greene Khoury, Kaitlyn Bristowe, Selma Blair, Nicky Hilton, Christa Allen, Kandee Johnson, Becca Tilley, and many others expressed their love, prayers, and condolences for Audrina and her family in the comments section.

Casey Loza also used Instagram to share the heartbreaking news of her daughter’s death; like Audrina Patridge, she expressed how difficult it was to write the caption, calling it the “hardest thing I have ever had to do.” She had difficulty finding the right words to say, which is understandable.