The Godfather. And Vito Corleone curses his family by not honoring the request of The Undertaker.
The Undertaker comes to Don Vito wanting his daughter's boyfriend and his friend killed because, " they made her drink whiskey and tried to take advantage of her. She kept her honor, so they beat her like an animal." "Beautiful girl. Now she will never be beautiful again."
After a discussion, the Don promises something, a gift on the day of his daughter's wedding.
"Give this to Clemenza. I want reliable people, people that aren't going to be carried away. I mean, we're not murderers in spite of what this Undertaker thinks."
By Vito saying this, we know The Undertaker asked that they be killed, and Don Vito refuses. But wait! No Sicilian can refuse any request on his daughter's wedding day.
Thus, curse. All their misfortune had nothing to do with the mafia. lol.