Life in Danger

If a friend of mine was in danger, hanging off a cliff or something bad I would definitely help them as much as I can, even though it's putting my life in danger. If a complete stranger needed help and if it put my life in danger I am not so sure because I don't even know the person. I mean I would help as much as I can but if the guy is going to die and you already know that then, no, I don't think I would help the person.