I am sure you have heard about the Kitty Genovese story, the most used event to describe the "bystander effect".
https://www.gothamcenter.org/blog/a-new-york-story-kitty-genovese
https://pmc.ncbi.nlm.nih.gov/articles/PMC8692770/
https://en.wikipedia.org/wiki/Murder_of_Kitty_Genovese
The horrific nature of the event is perhaps more relevant today.
Yep, I remember reading about that at university. A terrible case. It's crazy to me just how often the bystander effect is shown to be a thing.