Would you help, or not?

By now, many of you have probably read this story about an elderly woman who was mugged in England and tried to beg for help, but people ignored her.  How many times does that happen here, when someone needs help and people make assumptions in order not to help, assuming perhaps the person is drunk or is at fault in some other way (when maybe they are actually ill)?  Would calling police at least be a start if you are not sure whether someone is in trouble?