Caitlyn Jenner is "numb with shock" over the shock death of her longtime friend and manager Sophia Hutchins

A source told RadarOnline.com: "Caitlyn is numb with shock. She is absolutely devastated and can't believe what's happened. Sophia was a big part of her life."

TMZ previously reported that emergency services were called, but Sophia was pronounced dead at the scene. No one else is believed to have been injured in the accident.

Sophia took over managing Caitlyn's career in 2017 following the reality star's divorce from Kris Jenner. She appeared in her reality show I am Cait and even lived with the star at her Malibu home.

She explained the career move in an interview with the New York Times in 2019, insisting she just wanted to protect her friend at a vulnerable time in her life. Sophia told the publication: "I saw nobody was managing her, and there were all these people taking massive advantage.

"And I was saying: 'Caitlyn, if I don't step in here and start managing you, you're going to go broke'."

She added of their relationship: "Caitlyn is a parent to me. I have said that a million times. It is a parental, familial relationship."

The pair became so close, they were forced to deny speculation they were romantically involved.

Sophia is believed to have maintained a good relationship with Caitlyn's ex-wife Kris and daughters Kendall and Kylie Jenner, while she also appeared in a campaign for SKIMS - the clothing brand run by Caitlyn's stepdaughter Kim Kardashian.