In terms of this, firstly the issue of morality is debated ad nauseam amongst academics who have never had to save someone.

As a serving member in a maritime combat unit, we were taught that if an accident occurs, the value of the whole outweighs the value of the few; however, we are a unit and so every effort is made to save the few without endangering the whole or yourself but if it reaches the point where the saving of the few endangers the whole, then the few have to be sacrificed. Have i experienced this for real and in combat. yes and we were lucky.

Another morality question for the philosophists...you see a guy getting mugged by 5 others, do you walk on or go to his assistance?

The issue of your morality is dependant on the circumstance and occasion. Do you freeze/run around like a screaming girl/or take action and try to save someone?