I think there was a movie where part of the plot was that an adult character (woman?) was dealing with guilt from having caused her/his sibling (brother, I think) to be disfigured (or killed?). They were both kids, and she/he accidentally spilled a pot of boiling water from the stove onto him/her.
I have done tons of searches but have only come up with real life horrible stories.
Thanks!
Rain Man starring Dustin Hoffman and Tom Cruise has a scene where Dustin Hoffman’s character remembers accidentally burning Tom Cruise’s character in the bathtub when he was baby.