Diane Keaton's Son Duke Seen For First Time Since Her Death

Diane Keaton’s devastated son Duke was spotted leaving her L.A. home -- just a day after the legendary actress passed away at 79.

Here are the pics -- the 25-year-old cut a lone figure as he left the house Sunday and headed to his car, clearly mourning the loss of Diane, who adopted him back in 2001.

As you know, Diane passed away the day before, and the Los Angeles Fire Department tells TMZ they responded to her home at 8:08 AM Saturday, with an ambulance taking her to a local hospital.

Her cause of death is currently unclear.

Diane rose to fame in the 1970s with "The Godfather" franchise, won an Oscar for Best Actress for 1977’s "Annie Hall," and went on to star in a slew of other iconic roles.