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/ Source: TODAY
By Gina Vivinetto

Kristin Cavallari honored her late brother, Michael Cavallari, on Tuesday, the third anniversary of his tragic passing.

The former "Hills" star, 31, took to Instagram to share a happy photo of herself and Michael, and in the caption she opened up about how difficult it's been to accept that her big brother is really gone.

"Home from a busy morning and thinking of my brother," Kristin wrote. "Today is the 3 year anniversary of his passing and I think this year is one of the hardest— as it’s real now. He’s not coming back and the shock is finally gone."

She continued, "Today and every single day, Mikey, we miss you."

Michael, 30, went missing on Nov. 27, 2015, and authorities mounted a two-week search before discovering his Honda Civic abandoned about 100 feet from Interstate 70 in Utah on Dec. 10. Us Weekly reported that he was found in a "steep and very rocky area" after his car crashed in that spot, and he ultimately died of hypothermia. His death was ruled an accident.

During an appearance on "Hollywood Medium with Tyler Henry" earlier this year, Kristin revealed that Michael had been battling personal issues at the time of his death.

“He was dealing with some demons, there’s no doubt about it,” she shared with the show's star.

She also struggled to understand Michael's mysterious final hours.

“When my brother died, he got out of his car and he was walking,” she said. “I don’t think he wanted to be found. But did it get to a point where he got lost out there?”

The Cavallari family's devastating loss came just days after Kristin and her hubby, NFL star Jay Cutler, welcomed their daughter Saylor, 3. The couple also has two sons, Camden, 6, and Jaxon, 4.

In the year following her brother's death, grief-stricken Kristin took comfort in her children.

"I'm OK," she told People magazine in 2016. "I'm going to have good days and bad days, but I've really found a lot of strength in my kids. I couldn't just fall apart — I had a little baby to look after."

"When you lose someone," she added, "it really makes you realize how precious life is, and so I’m just thankful that I have my babies and I'm thankful for everything in my life."