Anne Hathaway "almost killed" her son on a jungle gym.
The 34-year-old actress took her 12-month-old son Jonathan to have some fun in the park, but things went wrong when she misjudged how fast a slide would be with them both on it.
Speaking on 'The Tonight Show Starring Jimmy Fallon', she said: "We had a great day today.
"I took him to a park... and he loves swings. And I noticed all these other kids were coming down the slide.
"And it looked like an unusual slide. Like, maybe it was built before they had child safety measures in place. It was gorgeous and I noticed the kids weren't going that fast so I said 'OK I'll bring Johnny on'.
"I pulled my skirt around me and I put Johnny there and we are going down the slide and now the moms are watching.
"But what I hadn't thought about was physics. So we just go around the corner and instead of slowing down like the other kids we speed up."
And the 'Les Miserables' actress was feeling "self-conscious" as the slide got faster and faster because she knew she had an audience.
She added: "It starts to go so fast and all the moms are watching and I'm so self-conscious.
"As it speeds up my thoughts slow down and I just look ahead and I get very serious and very focused and just think 'I must stick this landing'."
Anne, who is married to actor Adam Shulman, panicked in the moment but now laughs about what happened.
She said: "You know when you almost killed your child but you didn't. In the inside you're like 'Everything's OK. Walk it off, walk it off'.
"Then we went back to the swings and stayed there forever."