I️ have known, loved, and admired David Cassidy for 48 out of my 58 years. He has been as kind to me as any real brother could ever be. We’ve been through a lot together and he was always there for me. This loss is huge. RIP my dear friend. pic.twitter.com/eKdRyAuW2B— Danny Bonaduce (@TheDoochMan) November 22, 2017
"I have known, loved, and admired David Cassidy for 48 out of my 58 years," the 58-year-old Bonaduce, who now works as a radio show host, tweeted on Wednesday. "He has been as kind to me as any real brother could ever be. We’ve been through a lot together and he was always there for me. This loss is huge. RIP my dear friend."
Bonaduce starred on The Partridge Family as Danny, the middle child of the titular band. Cassidy played older brother Keith.
Bonaduce and Cassidy remained close friends until his death. When Cassidy announced his dementia diagnosis earlier this year, Bonaduce quickly asked fans to send their love to the former teen idol.
"David Cassidy once had a bigger fan club than Elvis & the Beatles. If you're a fan, now is a great time to send him your love & best wishes," Bonaduce tweeted in February.
"I’m a big believer in the power of prayers. Please keep my brother David Cassidy in yours. Thanks for all the love and support," Bonaduce tweeted last week after hearing about Cassidy's hospitalization.
Cassidy died on Tuesday from organ failure.
“On behalf of the entire Cassidy family, it is with great sadness that we announce the passing of our father, our uncle, and our dear brother, David Cassidy,” his family told PEOPLE. “David died surrounded by those he loved, with joy in his heart and free from the pain that had gripped him for so long. Thank you for the abundance and support you have shown him these many years.”
Shirley Jones, who was Cassidy's stepmother and played his mother on The Partridge Family, also issued a statement on Cassidy's death.
“My heart is with David’s daughter, Katie, his son, Beau, and with Shaun, Patrick, and Ryan, whom I know are deeply missing their brother today,” the 83-year-old Jones said. “Thank you for the enormous outpouring of affection you have offered our family at this difficult time.”