Is there any data about how many people suffer from "crush syndrome" versus the "bystander effect"? I'd guess the latter causes more suffering. I saw a man die

Is there any data about how many people suffer from "crush syndrome" versus the "bystander effect"? I'd guess the latter causes more suffering. I saw a man die, so did a first aid course. The tutor was unequivocal that trying to help is pretty much always better than not trying to help.