India, Oct. 14 -- Diane Keaton's son, Duke, is mourning the loss of his mother following her death at 79. The 25-year-old was seen for the first time since her passing, leaving the actress's Los Angeles home on Sunday, according to the New York Post. He wore all black, a backpack, and two silver cross necklaces, a quiet nod to Keaton's well-known layered "devoted nun" look from the 1990s.

Keaton adopted Duke and his sister Dexter, now 29, in her 50s and raised them on her own.

"Motherhood was not an urge I couldn't resist," she told Ladies' Home Journal. "It was more like a thought I'd been thinking for a very long time. So I plunged in."

Her children mostly stayed out of the public eye but joined her at her Hand & Footprint Ceremony i...