Well, after being trained in Red Cross First Aid,and being on anAmbulance Squad, and cross trained as a Medic, saving the people that can be saved is first nature. It is always best to save the person with a chance of survival. If you spend all your time on someone that will most surely die, you will have signed the death certificate on the other person that had a better chance of being saved.
This is also a question in apsychological test, and the answer is: you and your wife can always have another child. But if you choose to save your child, they will grow up without a mother, and you will often look at that child and wonder if you didn't do the wrong thing ! Together you and your wife would have still been a family !
But the answer is to save the person with the best chance of surviving first, and do what you can for the others second !
In life saving, even on the battle field, you should block any danger to you with the body of the injured. Because if you are incapacitated or killed, they will surely die also.
Bill