Pneumonia claims another icon: Diane Keaton's family reveals cause of death

Hollywood is still reeling after the death of legendary actress Diane Keaton, who passed away on October 11 at the age of 79.

Her family confirmed she died from pneumonia and shared a heartfelt message through People magazine: “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."

"She loved her animals and she was steadfast in her support of the unhoused community, so any donations in her memory to a local food bank or an animal shelter would be a wonderful and much-appreciated tribute to her.”

Her loved ones say her health declined suddenly and quietly. In her final months, she was surrounded only by her closest family, who chose to keep her condition private.

Many of her longtime friends reportedly didn’t even know what was happening until it was too late, something that has made the loss even more shocking for those who worked with her for decades.

Actor Steve Martin, who starred opposite Keaton in the 1991 classic "Father of the Bride", has been openly nostalgic about their time together. Keaton played Nina Banks, the stylish, warm and slightly frazzled mother of the bride, while Martin took on the role of the anxious dad, George Banks.

Their chemistry was effortless, the kind of on-screen pairing that felt like watching your own parents trying to hold it together during a wedding meltdown. If you’ve ever watched that film with your family on a Sunday night, you know exactly how comforting and funny the two of them were together.

But Martin’s memories of Keaton go even further back than Hollywood. In an Instagram post, he revealed that the two worked together long before fame entered the chat, back when they were both acting students at Santa Ana College in southern California.

“This playbill is from a 1964 college production of Carousel. Diane ‘Hall’ (Keaton) is the lead; I’m a stage hand,” he captioned the post, sharing a photo of the playbill.

The nostalgia and affection were obvious; they had gone from theatre kids to screen icons together, even if their paths had only crossed publicly again decades later.

Keaton, best known for her roles in "Annie Hall", "Something’s Gotta Give", "The First Wives Club", and so many comfort-watch classics, died in California after what insiders say was a “very sudden” decline. She remained private to the end, a trait that those close to her respected.

Her passing has once again put the spotlight on pneumonia, an infection many still underestimate. It can be viral, bacterial or fungal. While it sounds like something you shake off with antibiotics and bed rest, it’s actually one of the deadliest respiratory illnesses, especially for older adults.

We’ve lost several icons to pneumonia over the years. "Star Trek" actor Leonard Nimoy died from complications related to it. Aretha Franklin, who battled other illnesses, ultimately faced pneumonia near the end of her life.

South African icon Mandoza experienced pneumonia during his cancer battle.

Older adults are particularly vulnerable as the immune system naturally weakens with age, and even a mild cold can spiral into something far more dangerous.

Keaton’s case is a reminder that pneumonia remains a threat.