Robin Williams' final post on social media was a sweet message to his daughter. The actor shared an adorable throwback photo on Instagram of his daughter in his arms.

"Happy Birthday to Ms. Zelda Rae Williams! Quarter of a century old today but always my baby girl. Happy Birthday @zeldawilliams Love you!" he wrote as the caption on July 31.

Zelda, an actress known for House of D and Were The World Mine, is Williams' daughter with his second wife, Marsha Garces. The two were married from 1989 to 2010 and also have a son together named Cody. Williams is survived by another son, Zachary, with first wife Valerie Velardi.

The actor, whose career spanned almost 40 years, was found dead from an apparent suicide on Monday in California. He was 63.

"He has been battling severe depression of late," his rep Mara Buxbaum said in a statement. "This is a tragic and sudden loss. The family respectfully asks for their privacy as they grieve during this very difficult time."

The Oscar winner's current wife, graphic designer Susan Schneider, said: "This morning, I lost my husband and my best friend, while the world lost one of its most beloved artists and beautiful human beings. I am utterly heartbroken. On behalf of Robin's family, we are asking for privacy during our time of profound grief. As he is remembered, it is our hope the focus will not be on Robin's death, but on the countless moments of joy and laughter he gave to millions."

The Crazy Ones star - whose famous roles include Mrs. Doubtfire, Jumanji, Good Will Hunting and many more - was working on the third installment of Night at the Museum before his sudden passing.

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