Model Cindy Crawford is “heartbroken” over the sudden death of her 27-year-old son Presley Gerber, a friend says.

Gerber died on Sunday (US time) from an apparent overdose and cardiac arrest, and Crawford is said to still be “completely in shock”.

“Cindy is completely in shock over Presley’s devastating death. She is heartbroken,” a source told People.

Police records indicate a call for an overdose in the Santa Monica-area on Sunday morning. The dispatch call also noted cardiac arrest.

Another insider close to Kaia Gerber, Gerber’s  25-year-old sister, has revealed that the family are “in total shock”.

“They are saddened beyond words,” the friend said.

“Kaia loved that Presley was so open about his struggles; his family was so proud that he was finding strength in helping others.”

Gerber had previously been candid about his struggles with mental health and substance abuse, explaining that he didn’t want other people to repeat his own “mistakes”.

“Having struggled with mental health, depression and some other things that come along with that, I think that whether I help one person or a hundred people get out of that place that I was in at one point in my life, that’s all I need to do,” he told the Studio 22 podcast.

He said helping other people with similar issues had become his life goal.

“[Mental health] is an issue. It is such a big part of my life. It’s a 24/7 job, and there’s so much to it. That’s really what I want to do: help people, whether you’re depressed, you’re struggling with something that is having a negative effect on your body. I mean it could be anything, and there’s no judgment,” Gerber said.

“I’ve seen a lot of stuff and I’ve learned a lot of things. What I hope I can do is have made the mistakes for some other people, so they don’t have to make the same mistakes that I made.”

In September, Kaia Gerber also reflected on her brother’s addiction struggles, and explained how it had shaped her own character, too.

“When something like that happens in a family, it kind of levels everyone,” she told Vogue.

“I think that’s also why I started to self-​identify as the easy one and never wanted to ask for help. Because it felt like too much to have two children who were needing.”