One of Diane Keaton's closest friends has spoken out after the Hollywood star's "unexpected" death. The Academy Award-winning star passed away in California at age 79. Grammy and Oscar-winning songwriter Carole Bayer Sager recalled her final visit with Diane just weeks before her death, and was stuned by her appearance.

She said: "I saw her two or three weeks ago, and she was very thin. She had lost so much weight. She had to go to Palm Springs because her house had been damaged inside, and they had to clean everything. She was down there for a while, and when she came back, I was kind of stunned by how much weight she'd lost."

She added: "She was a magic light for everyone. I just loved her. She was so special, she just lit up a room with her energy. She was happy and upbeat and taking photographs of everything she saw. She was completely creative; she never stopped creating."

The Academy Award-winning performer gained recognition for her roles in productions such as The Godfather, Annie Hall, The First Wives Club, and Something's Got To Give.

Keaton frequently collaborated with filmmaker Nancy Meyers on ventures such as the Book Club franchise.

Throughout her illustrious career, she garnered numerous awards, including an Oscar, a BAFTA, and a Golden Globe Award, and was nominated for two Emmy Awards and a Tony Award.

The late actress had romantic relationships with Hollywood heavyweights such as Woody Allen, her Godfather co-star Al Pacino, and Warren Beatty.

Recent revelations about Diane's health have been surfacing. A close friend of Diane's revealed to PEOPLE Magazine: "She declined very suddenly, which was heartbreaking for everyone who loved her. It was so unexpected, especially for someone with such strength and spirit."

The insider further shared: "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."

Carole Bayer Sager also recounted her last visit with the Hollywood star to the same outlet, remembering: "I saw her two or three weeks ago, and she was very thin," Sager says. "She had lost so much weight".