Kristin Cavallari's brother died from hypothermia.
Michael Cavallari - the older sibling of the 'Hills' star - passed away two months ago from accidental causes after he crashed his car during extreme temperatures while passing through a rocky and rural part of southern Utah, an autopsy has revealed, according to gossip site TMZ.
Grand County Sheriff Steven White announced on Tuesday night (09.02.16) that they are still waiting on toxicology reports to find out if Michael had any drugs in his system but the recent autopsy results were enough to close the case.
Michael initially sparked speculation he'd committed suicide after his Honda Civic was found abandoned two weeks after he went missing at the beginning of November.
However, his body was later found at the bottom of a steep hillside on December 10, roughly two weeks after his vehicle was found, about 200 miles south of Salt Lake City.
Police believe Michael may have started walking towards the city to seek help after he smashed the car but questions about what actually happened may never be answered.
Kristin, 29, was left devastated by her brother's death but claimed, at the time, her baby daughter Saylor, now three months, was providing her some solace during the tough time.
She said: "My little angel, Saylor. She has been my light throughout this whole thing and has given me so much strength. Thank you baby girl for coming when u did."
Kristin also has sons Camden, three, and Jaxon, 21 months, with her husband Jay Cutler.