Originally Posted by o-dog
it's actually called the bystander effect. people just assume that "someone else" will help, so they don't.
There are other reasons too. I was dating a gal one evening and she (a nurse) drove right past an accident that had just happened. The car involved had passed us not 30 seconds before at about 90 mph. She told me that she was afraid that she could get sued if she tried to help. But there was no penalty for not stopping.
No penalty for her at least. Both teens in the car died, and I heard announcements on TV asking for help in identifying them for about a week.