The talent manager and former husband of Kelly Clarkson died of melanoma, a form of skin cancer, on Thursday, Aug. 7

Brandon Blackstock’s official cause of death has been confirmed.

“Brandon Blackstock passed away peacefully at his home in Butte, Montana on August 7th under hospice care surrounded by his family,” Silver Bow County Coroner Dan Hollis tells PEOPLE, confirming that Blackstock’s cause of death was melanoma, a form of skin cancer; the manner of death was natural causes.

The talent manager died on Thursday, Aug. 7, a rep for the family confirmed in a statement to PEOPLE the same day.

“It is with great sadness that we share the news that Brandon Blackstock has passed away,” the statement read. “Brandon bravely battled cancer for more than three years. He passed away peacefully and was surrounded by family. We thank you for your thoughts and prayers and ask everyone to respect the family’s privacy during this very difficult time.”

The news came just one day after his ex-wife Kelly Clarkson, 43, revealed that Blackstock was ill, and she would be postponing the rest of her August Las Vegas residency dates in order to look after the former couple’s daughter River, 11, and son Remington, 9.

“Unfortunately, I need to postpone the remainder of the August Studio Session dates in Las Vegas,” she wrote in an Instagram post at the time.

Brandon Blackstock and Kelly Clarkson in Santa Monica in January 2020. Jeff Kravitz/FilmMagic

Clarkson continued: “While I normally keep my personal life private, this past year, my children’s father has been ill and at this moment, I need to be fully present for them. I am sincerely sorry to everyone who bought tickets to the shows and I so appreciate your grace, kindness and understanding.”

A source told PEOPLE that Clarkson — who finalized her divorce from Blackstock in 2022 — has “been devastated” for her kids amid their father’s illness.

“When she found out that he was sick, she remained protective of him for their sake,” the source said. “Kelly has always tried to keep things classy. It became clear earlier this year that Brandon was not doing well. She’s been devastated for the kids.”

Following Blackstock’s death, Clarkson is “staying strong” for their children, an insider told PEOPLE.

“Kelly and Brandon had their ups and downs, but at the end of the day, he was the father of her children and she is absolutely heartbroken for them,” the insider added. “Her kids are her entire world, and she’s staying strong for their sake.”

Brandon Blackstock.Shelby Blackstock/Instagram

In 2023, Clarkson opened up about co-parenting with Blackstock, and explained that her children and their feelings were her top priority.

“I ask my kids every night when we’re snuggling and I put them to bed, ‘Are you happy? And if you’re not, what could make you happier?’ ” Clarkson said on Angie Martinez’s IRL podcast. “Especially the past two years … it kills me [but] I want them to be honest so I don’t ever say, ‘Oh God, don’t tell me that,’ but a lot of times it would be like, ‘I’m just really sad. I wish Mommy and Daddy were in the same house.’ They’re really honest about it. I’m raising that kind of individual.”

She continued, “I just sit there and I’m like, ‘I get it. I’m from a divorced family as well. I get it. That sucks. But we’re going to work it out. And you are so loved by both of us.’ ”

Blackstock is survived by his sons Seth and Remington, daughters Savannah and River, grandson Lake, father Narvel Blackstock, mom Elisa Gayle Ritter and siblings Shelby, Shawna and Chassidy.