Francis Ford Coppola has revealed his new film helped him explore his feelings about the death of his son.
The director - whose new film Twixt stars Val Kilmer as a writer who gets entangled in a murder mystery involving a young girl - lost his eldest son Gian-Carlo in a tragic speedboat accident in 1986.
Speaking at the Toronto International Film Festival, Francis fought back tears as he explained: "I didn't know that it would lead me to something that I haven't ever admitted to myself.
"Every parent feels that they're responsible for what happens to your kid and you don't let yourself off on that. I didn't realise how much I felt personally responsible for what happened those 24 years ago, because I should have been there."
Budding film producer Gian-Carlo, 22, died instantly when the boat he was travelling in, driven by Ryan O'Neal's son Griffin, struck a tow line.
An emotional Francis added: "It was the time to own up to the fact that deep down in my heart I felt responsible because I could have gone, he wanted me to go, and somehow it just took me there and I'm grateful... that I could have that understanding.
"Whether I'll feel better I don't know. But I do think parents, no matter what happens to your kid, they could say oh he had a cold in nursery school, you feel responsible. In my case I felt really responsible, and felt it was appropriate to have the character Hall that Val was playing."