Diane Keaton's Health 'Declined Suddenly': Details on Cause of Death

Diane Keaton died on October 11, her family confirmed to People. She was 79.

Diane Keaton's Health and Cause of Death

A spokesperson for the legendary actress told the outlet, "There are no further details available at this time, and her family has asked for privacy in this moment of great sadness."

However, a separate source later revealed the Annie Hall star's health "declined very suddenly" in the months leading to her passing.

"[It] was heartbreaking for everyone who loved her," a friend told People shortly after her death. "It was so unexpected, especially for someone with such strength and spirit."

The source continued, "In her final months, she was surrounded only by her closest family, who chose to keep things very private. Even longtime friends weren’t fully aware of what was happening."

Little is currently known about her exact cause of death.

Diane Keaton's Legacy

The Godfather actress was beloved for decades on and off the screen. She rose to fame in the 1970s after landing her role in Francis Ford Coppola's trilogy. She went on to earn an Academy Award for Best Actress for her titular role in 1977's Annie Hall.

Keaton -- who was born Diane Hall -- was never married, despite high-profile romances with stars such as Woody Allen, Al Pacino and Warren Beatty.

She adopted two children: daughter Dexter Keaton in 1996 and son Duke Keaton in 2001.

"I didn't think that I was ever going to be prepared to be a mother," she told Ladies' HomeJournal in 2008. "Motherhood was not an urge I couldn't resist, it was more like a thought I'd been thinking for a very long time. So I plunged in."