In a tragic incident at Los Angeles’ popular Runyon Canyon, William Hasley, a close friend and biographer of Caitlyn Jenner, collapsed and died while hiking. This unfortunate event unfolded on Saturday, marking the end of a life known for its literary contributions and personal connections.
Hasley, who was 78 years old, was found off Nichols Canyon Road near Hollywood Boulevard. Emergency responders arrived at the scene around 6:42 p.m., but despite their efforts, they were unable to revive him, according to reports from The New York Post. He was pronounced dead shortly thereafter.
An official from the Los Angeles Fire Department noted, “LAFD Air Operations lowered rescuers to the patient, and medical treatment was administered,” highlighting the efforts made to save Hasley’s life.
The cause of death remains undetermined as the Los Angeles County Medical Examiner’s Office continues its investigation. The community awaits further details to understand the circumstances surrounding this sudden loss.
Hasley was renowned for his collaboration with Caitlyn Jenner on her 1996 self-help book, “Finding the Champion Within,” published by Simon & Schuster. The book delves into Jenner’s journey as an Olympic gold medalist, and through this project, Hasley and Jenner developed a deep friendship.
Finding The Champion examined Jenner’s life as an Olympic gold medalist – with Hasley revealing the pair became ‘fast friends’ during a past project before he was commissioned to write the book.
Caitlyn Jenner’s friend and biographer William Hasley has been identified as a hiker who collapsed and died on LA’s Runyon Canyon on Saturday
Hasley, 78, who was married to actress Robin Riker briefly in 1987, was discovered off Nichols Canyon Road near Hollywood Boulevard at 6.42pm, with air rescuers trying in vain to save his life per The New York Post . He was declared dead shortly afterwards – pictured 1980s
This is the second tragedy in less than a year to strike Jenner. The former Olympian’s confidante and manager Sophia Hutchins was killed in July 2025 after she plunged 350ft down a cliff near the reality star’s Malibu home; seen in 2020
He was also a screenwriter known for his work with Universal Pictures, Warner Brothers, and 20th Century Fox.
Hasley was known for his brief marriage to Brothers actress Robin Riker in 1987.
At the time of his death, Hasley worked as an instructor in screenwriting at UCLA with a source telling the Daily Mail that Hasley spoke to several people on campus on Friday. ‘Various people spoke to him on Friday and he didn’t have any health issues.’
Hasley’s biography on the UCLA website reads, ‘When Will isn’t meeting a deadline, you’ll most likely find him fighting City Hall over an environmental issue, writing an article, teaching a writing class at UCLA, volunteering in a soup kitchen, or speaking to a youth organization.
‘Will’s a great sports enthusiast. He’s often playing in a Celebrity Golf Tournament, Showbiz Softball League, or riding horses with the infamous Hole in the Wall Gang.’
The Daily Mail has contacted representatives for Jenner and UCLA for comment and has yet to hear back.
This is the second tragedy in less than a year to strike Jenner.
The former Olympian’s confidante and manager Sophia Hutchins was killed in July 2025 after she plunged 350ft down a cliff near the reality star’s Malibu home.
The 29-year-old’s ATV is believed to have struck the bumper of a moving car and was thrown down a ravine.
Hutchins, like Jenner, was transgender and cited the father-of-six as the inspiration for coming out in college back in 2016.
Hasley, 78, was discovered off Nichols Canyon Road near Hollywood Boulevard at 6.42pm, with air rescuers trying in vain to save his life . He was declared dead shortly afterwards – pictured Runyon Canyon
Hasley worked as an instructor in screenwriting at UCLA with a source telling the Daily Mail that Hasley spoke to several people on campus on Friday. ‘Various people spoke to him on Friday and he didn’t have any health issues’ – pictured with Riker in 1986
In 2017, Hutchins moved into Jenner’s home and began working as the star’s manager, taking over the role from Jenner’s ex-wife Kris Jenner, 69, after their 2015 divorce.
Hutchins was in Jenner’s inner circle for over a decade after she came out as a transgender woman in 2015.
Hutchins met Caitlyn that year and appeared in multiple episodes of the television documentary series I Am Cait, a spin-off of Keeping Up With The Kardashians.
Despite living under one roof, Hutchins previously told The New York Times that they ‘were never romantically involved’, insisting it was all about work and friendship.
