Kristen Cavallari’s brother Michael Cavallari’s death may have been caused by prolonged exposure to the elements, authorities in Utah have said. Michael’s body was found on Thursday (December 10th), two weeks after he had first gone missing.

Kristen CavallariKristen Cavallari’s brother Michael was found dead on Thursday.

Grand County Sheriff Steven White told Fox News that frigid weather in the area might have played a factor in his death. Nighttime temperatures were said to be at or below freezing in the area around the time his car was found against a small embankment.

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Officials told E! News that "There were no signs of major trauma and no suicide note," and “cops did not find any evidence of drugs or alcohol either.” The official cause of death is still pending toxicology reports, which are expected to be released in the next 6-8 weeks.

On Instagram, Cavallari posted a tribute to her brother, sharing a picture of the two siblings as children. "My heart is in a million pieces,” Cavallari wrote. "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.”

Speaking to People magazine, Michael’s long-time friend Bret Powers said the 30-year-old had been working to get his life back on track in recent months. "He was doing that and doing real well," Powers told People. "Everything seemed to be going well in his life, and I just don't know what caused this."

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"He's a goodhearted guy and he was always someone you could count on if you needed anything. He wasn't out for himself ever. Deep down inside he had a great heart and had a real good ambition in life and it's unfortunate he had to go this early. I'm still in shock."