A classic Hollywood actress and her husband were found dead inside a running vehicle on the side of a California interstate, authorities said.

Judith Sheldon, 84, and her husband, Wylie Sheldon, 86, were discovered on the evening of June 15 inside a Jeep Compass parked on the shoulder of Interstate 5 near Redding, according to the California Highway Patrol.

The grim discovery was made around 5:46 p.m. north of Fawndale Road, according to reports.

Sheldon, who was driving the SUV, was found with her husband in the passenger seat. The vehicle was still running when a CHP officer came upon it, the San Francisco Chronicle reported.

A second officer arrived to help, and medical personnel rushed to the scene. But despite efforts to save them, both Judith and Wylie were pronounced dead.

Authorities have not released a cause of death.

The CHP’s Northern Division Investigative Services Unit is now investigating the mysterious deaths.

Judith Sheldon, born Judith Wyler in Los Angeles, came from Hollywood royalty. She was the daughter of legendary Oscar-winning filmmaker William Wyler and actress Margaret Tallichet.

Her father directed some of the most famous films of Hollywood’s golden age, including Ben-Hur, Mrs. Miniver and Roman Holiday.

Judith also appeared on screen herself during the 1950s. Her credits included The Errol Flynn Theatre, The Buccaneers and BBC Sunday-Night Theatre, according to IMDb.

She also had a small appearance in the beloved 1953 classic Roman Holiday, which starred Audrey Hepburn and Gregory Peck and was directed by her father.

Later in life, Judith, who was also known as Judy Wyler Sheldon, became a respected figure in San Francisco’s arts world.

She was a passionate advocate for preserving silent films and served as board chair for the San Francisco Silent Film Festival.

The San Francisco Chronicle described her as a San Francisco arts patron who was deeply connected to the film community.

In a 2007 interview, Sheldon said her love for silent film preservation grew after she attended a retrospective of her father’s early work in Pordenone, Italy.

She was also listed as a co-chair for San Francisco Performances’ 43rd season gala.

Now, her sudden death alongside her husband has left questions unanswered as investigators work to determine what happened on the side of the busy California highway.

Anyone with information about the incident is being asked to contact CHP investigators at 530-242-4300.