While Diane Keaton’s death Saturday came as a shock to many movie fans, it wasn’t a surprise to those close to her because she had been suffering from an unnamed illness for a while before succumbing to pneumonia, TMZ reported Thursday.

Earlier this week, Keaton’s family issued a statement to People, saying she died of pneumonia last Saturday, as they also expressed gratitude to fans for their outpouring of support.

“The Keaton family are very grateful for the extraordinary messages of love and support they have received these past few days on behalf of their beloved Diane, who passed away from pneumonia on October 11,” the statement said.

TMZ said it spoke to a longtime confidant of Keaton’s who said that the Oscar winner had been struggling with an unnamed illness, leading up to her death. Because of the decline in her health, her death therefore did not come as “a shock,” the friend said. TMZ said this news means there probably was an underlying cause or contributing factors in her death.

A friend of the “Annie Hall” star also told People that her health had “declined very suddenly” in recent months and that she chose to withdraw from public life in order to spend time with her “very closest family.” Although Keaton was reportedly known for being spotted walking her dog, Reggie, in her neighborhood, those sightings stopped before her death.

TMZ reported earlier this week that Los Angeles Fire Department paramedics responded to her home at 8:08 a.m. Saturday and transported one person — whom sources confirmed to be Keaton — to a nearby hospital where she was pronounced dead.