PHOTOS: Kristin Cavallari Mourns The Mysterious Death Of Her Brother — Heartbreaking Pics!

Former reality star Kristin Cavallari wandered Chicago after The National ENQUIRER reported yesterday that authorities had found the body of her missing older brother Michael. The 28-year-old Utah man had been missing for three days — with his 2014 Honda Civic found abandoned on Nov. 27 on I-70 in Utah. Kristin's worst fears were confirmed as the state's Grand County Sheriff's Office said: "At approximately 10:30 a.m. search crews located remains believed to be that of Michael Cavallari. At this time, the body is being transported to the Office of the Utah Medical Examiner for positive identification and to determine the cause of death."

The National ENQUIRER had earlier reported that Michael, 30, had been arrested with a loaded shotgun in his possession just four days before his car was found. A woman had called the Orange County Sheriff's department saying that he had been outside of her apartment with the weapon, and that the two had argued earlier in the week. She told the police that Michael had been continually loitering outside her apartment. Investigating officers found Michael at the address, and he admitted to having a loaded shotgun in his car — but denied any wrongdoing.

"My heart is in a million pieces," Kristin, 28, wrote on Instagram — having posted a photo of them together as children. "Mikey, I could always count on you to make me laugh. You had such a good heart and will be forever missed. I'm at a loss for words but I know u are in a better place and finally at peace. I love u so much RIP."

Kristin — now married to Chicago Bears quarterback Jay Cutler — enjoyed fame as a reality star on the MTV series "The Hills" and as a contestant on "Dancing With the Stars." Arrangements have yet to be announced for Michael's funeral,. "This is a very painful time and we are still processing it all," Kristin said in a statement. "We kindly ask everyone please respect our privacy during our time of grieving."