Nicole Kidman "laughed" when she saw her father's dead body - and her mother had to "slap [her] face" to bring her back to reality

Speaking at an FYC event for the show in Los Angeles over the weekend, she said: "When we go to the morgue when we're told our son is there ... I just said, 'I'm gonna try something because this is actually from my own life' - not where I went to a morgue, but when my father passed away, and I laughed.

"Because it was so devastating when I saw his body ... and I had the most awful reaction, which was I started to shake and laugh. And I'm like, 'That's what Margaret would be feeling.'

"... My mom looked at me and she actually had to slap my face and say, 'Nicole, snap out of it,' because I was so short-circuited in my brain... She said, many times ... 'Snap out of it.' "

Noting it was "very weird and strange" to see her father's body, Nicole admitted she felt "ashamed" of her reaction.

She said: "[I was] so ashamed to talk about it, but at the same time I go, 'But it's real.' And it's based in the deepest love and not being able to handle a situation."

The Australian star is pleased her real reaction was echoed in the scene because so many viewers have experienced the same "awful" response to tragedy.

She said: "So many people have come up to me subsequently and gone, 'Yeah, I've had it,' where you start to shake and instead of tears rolling, you are quivering with this weird laughter. It's awful. Awful."