India, Oct. 12 -- Diane Keaton's health deteriorated quickly in the months before her death, according to those close to her. Months before her death, she listed her longtime "dream home" for sale, a property she had once said she planned to stay in permanently, according to People.

"She declined very suddenly, which was heartbreaking for everyone who loved her," a friend of the Oscar-winning actress told PEOPLE. "It was so unexpected, especially for someone with such strength and spirit."

The friend added, "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."

The five-bedroom, seven-bath Los Angeles estate was priced...