prompted an outpouring of emotional tributes on Twitter. Celebrities, including former colleagues, wrote about their memories of the late singer and actor.
The teen heartthrob star of the 1970s hit "The Partridge Family," Cassidy went on to have a long show business career, although he battled alcoholism later in life. He died at age 67, surrounded by family, his publicist said Tuesday.
Cassidy's nephew Jack tweeted, "I don't think I'm alone in saying that we will all miss him."
"Partridge Family" co-star Danny Bonaduce said Cassidy was "as kind to me as any real brother could ever be."
Other former child stars of the same era remembered Cassidy's warmth. Maureen McCormick of "The Brady Bunch" said Cassidy was always "so kind and sweet" to her, and confessed, "Deep down I dreamt of being a Partridge."
Jimmy Osmond, who launched his singing career in the 1970s and appeared with his siblings on "Donny & Marie," said he was grateful to have worked with Cassidy.
Several female stars confessed that Cassidy was their childhood crush. Dana Delany posted a clip of the time she got to sing "I Think I Love You" with Cassidy.
Corey Feldman said Cassidy inspired him to pursue a career in acting and singing.
Bryan Cranston and Julie Benz tweeted fond memories of working with him. Cranston called him an "exceptional person & talent."
Other stars praised the kindness and vocal talent of "the biggest heartthrob of the 70s."
Cassidy said in February that he was suffering from dementia.
"I was in denial, but a part of me always knew this was coming," he told People magazine about his diagnosis. His mother had suffered from the disease.