Caitlyn Jenner's Biographer and Friend Found Dead on Los Angeles Hiking Trail

Caitlyn Jenner lost of one of her longtime friends and collaborators.

William Hasley, who served as the ghostwriter for Jenner’s 1996 motivational book Finding the Champion Within, died on June 6, according to records from the Los Angeles County Medical Examiner.

The 78-year-old accomplished writer was discovered near Runyon Canyon in Los Angeles after an apparent medical emergency during a hike.

According to the Los Angeles Fire Department, emergency crews responded to the scene and quickly launched a rescue operation.

Hasley was found in a remote area near the popular hiking destination. Air rescue teams were dispatched in an effort to reach him and provide assistance.

“LAFD Air Operations lowered rescuers to the patient,” an LAFD spokesperson said in a June 9 statement to the outlet, “and medical treatment was administered.”

Despite those efforts, Hasley was pronounced dead at the scene.

At this time, officials have not released a cause of death.

News of Hasley’s passing came as a shock to people who knew him. A neighbor who lived near Hasley’s home recalled seeing him shortly before the tragedy occurred.

“I just saw him on Saturday carrying groceries,” the neighbor told The New York Post. “It’s very sad he had to die all alone like that.”

Hasley and Jenner first connected while working on an Olympics-related project years before they collaborated on Finding the Champion Within.

The self-help book, which was published in three decades ago, focused on Jenner’s athletic achievements and featured a 10-step program designed to help readers improve and refocus their lives.

In his biography, Hasley said the pair became “fast friends” before Jenner eventually asked him to help write the book.

Beyond his work with Jenner, Hasley built an impressive career in Hollywood as both an author and screenwriter.

He contributed to beloved animated series including The Smurfs and Fat Albert and the Cosby Kids. His involvement with Fat Albert later led to work with the Special Olympics, a cause that was especially meaningful to him given his own athletic background as a former football player and cross-country athlete at Marshall University.

Throughout his career, Hasley also developed the pilot Borderline Heroes, which was sold to ABC. He wrote the comedy pilot Steeltown for Castle Rock Entertainment and worked on the pilot Brooklyn District.

His résumé continued to grow with projects alongside Oliver Stone and Gerald Green, including writing work on Defiance. He also penned episodes of The Young Riders and Swift Justice.

Those closest to Hasley knew him for much more than his professional accomplishments.

“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,” the biography said. “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.”

Hasley’s death comes less than a year after Jenner suffered another devastating loss.

Former manager and close friend Sophia Hutchins died on July 2, 2025, following an ATV accident near Jenner’s Malibu home. She was 29 years old.

At the time, Jenner spoke candidly about the emotional toll of losing someone so close to her.

"Recently my good friend Sophia passed away in a tragic accident," Jenner said on FOX News @ Night at the time. "But for the last seven weeks, I've been dealing with death, and it's so difficult."