I've heard a number of conflicting reports about the Kitty Genovese case you're talking about, but the more reliable sources indicate that when she was stabbed, it punctured her lung. Fifty-seven bodily stabs would be hard-pressed not to. She would not have been making loud noises when dying. I think it's kind of reasonable to assume that people yelling at each other on a city street is none of your business. Also, being in the middle of the street doesn't guarantee that you're in a logical line-of-sight from people in the buildings.

I'm not saying the Bystander Effect and related things don't exist, or that any of these things aren't awful. People have been raped in broad daylight, and the people walking by either didn't notice by willful misinterpretation (people don't get raped in broad daylight! I must just be seeing an argument or something!) or a perpetual responsibility shift onto the next person over. Just, from what I've heard, the most famous case isn't actually a good example.

The Wikipedia article (Murder of Kitty Genovese) has a link to some of these sources, several of which are in psychological journals, which, by purpose searching for the truth, I'd value over newspapers and fictional sources that want to dramatize things.