Willie Aames Says 'I'm Gutted' After Eight Is Enough Costar Adam Rich's Death: 'My Only Little Brother'

Eight Is Enough's Willie Aames is grieving the loss of his longtime friend Adam Rich.

After news of Rich's death broke on Sunday, Aames shared his love for his former costar on Facebook.

"This morning [my wife] Winnie woke me with the heartbreaking news of Adam Rich's passing," he wrote. "I'm gutted. Adam was more than a colleague. He was very much my only little brother. A lifelong friend."

RELATED: Adam Rich, Star of Eight Is Enough, Dead at 54

He also detailed some of Rich's thought processes in the past few years, stating the actor considered returning to Hollywood. "These last few years Adam had dreams of renewing his career. He was one of those kid actors that our generation will always remember."

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Aames also remembered Rich's role as Nicholas Bradford on Eight Is Enough, with Aames beside him as Nicholas's brother Tommy Bradford. "I can't tell you how many parents have told me they named their first child 'Nicolas' after his Eight Is Enough character. The diminishing fraternity of kids that grew up in the golden years of family television has lost another of our own. I will miss him deeply."

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He ended the post, "Rest 'A.R.' You were the cutest TV kid of them all," adding the hashtag "#heartbroken."

RELATED: How Eight Is Enough Star Willie Aames Found True Love with a Former Fan: 'It Was Meant To Be'

Eight Is Enough's Betty Buckley also shared an emotional tribute to Rich online. "Adam Rich was a light and my young pal for the four seasons I was blessed to work with him on Eight Is Enough," she captioned an Instagram gallery of photos. She also called him, "so sweet, funny, fresh and natural. He brought a lot of joy to all of us on the show and to our audiences."

Buckley said she and Adam had "remained friends all of these years," and called his death a "shock."

"Sending my love and deepest condolences to his friends and family," she wrote. "In recent years Adam dedicated himself to providing inspiration for others with mental and emotional illness. I will miss him greatly ❤️❤️💔"

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Rich died on Sunday at the age of 54. A cause of death has not been revealed, though case notes from the Los Angeles County Medical Examiner's office confirm that Rich died in his home and indicate that further investigation is needed to determine an official cause of death.

A law enforcement source ruled out foul play in conversation with TMZ, who was first to report Rich's death.

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In addition to his time on Eight Is Enough, Rich also appeared ABC's Code Red in 1981 and 1983's Dungeons & Dragons, in which he voiced teenage wizard Presto the Magician.