People say they cannot predict how one would react in such a scenario, but I'm going to be bold here and doubt the validity of that statement. I presume that many folks can predict precisely how they would react, but they're ashamed of it, so they deny it, they push it aside and attempt to reassure themselves that their reaction is the smart, sensible thing to do, comforting themselves further with any number of tangible reasons not to get involved.
Maybe it's just me, but I know exactly how I would react... I would be afraid, shocked, I would probably have the urge to flee, or depending on the situation an urge to stay and fight. Natural emotional responses towards danger, how practically anybody who wasn't trained to deal with such situations would respond. The difference is, I don't hide from it, I acknowledge it as something that I don't like about I'm myself, something that I want to change. I don't want to be afraid, I want to be brave, I want to be something more than just an assortment of biological material driven by a series of emotional/instinctive impulses which are inherently selfish because they are primarily intended to help ensure the survival of the individual organism, with any urges to protect others just being more selfish instincts intended to help ensure the survival of family. I want to be the person who springs into action and helps others in danger, even if it means putting myself in danger because I admire people like that. Not for selfish reasons like the desire for recognition or respect from others, but because it is the right thing to do.
I'll admit that it is a struggle, it's easier to ignore others in need, and there are plenty of valid reasons not to get involved in the affairs of others, but regardless, that isn't who I want to be. I've been in danger myself, yet everyone just ignored it because it wasn't their problem, I spent years hating them for that, for their callous indifference towards myself and others, until I got older and realized that although I had never seen anyone else in danger like I was, my first response towards others in need was that it wasn't my concern.
I want to overcome that weakness of character, so I acknowledge that it exists within me and I use that as motivation to change, to become stronger and push myself outside of my comfort zone.
So yeah, I know precisely how I would react. I would put aside my fear and intervene, regardless of the danger involved, because frankly I would much rather die a hero and succeed at being something more than live out an otherwise empty existence in which I never did anything particularly meaningful.
Granted, it's easy enough for me to say, because unlike others I don't have an awful lot to lose, there's nobody who needs me, much less who couldn't survive in my absence, but even if that were to change, I doubt that my feelings on the matter would. I still couldn't turn a blind eye to someone else in danger just because I have much to lose.
In the end, I acknowledge that I don't have what it takes to be a full-time hero like a Policeman, Firefighter, EMT, or anything else like that, otherwise I would be employed in such a position and devote my life to it. But should I ever encounter someone in need with nobody else willing or able to help them, then I will lend a hand.
Now maybe I'm dead wrong here, maybe I'm just projecting my own guilt regarding past insecurities upon others. Like I said, I acknowledge my weaknesses so that I might overcome them through effort and determination, but assuming that I'm right and any of what I've been rambling about resonates with anyone else here, then I implore you, don't hide from something that you don't like about yourself. Do what you feel is right, regardless of your fears, acknowledge it, rise above it, and if you ever feel the call to aid someone in need, then answer it. Because believe me, it's better to die doing what you know is right than living with regret over what you failed to do.
And hey, if you truly feel that there are others who need you and cannot carry on without you, then by all means, stay as far away from a dangerous situation as possible for their sake, but don't turn around and dishonor the dead for their heroism by criticizing their brave decision to intervene on the behalf of others. Surely they left behind a family of their own who will sorely miss them, but perhaps the heroism of their dearly departed helps to ease their pain, and the last thing they would want to see is their sacrifice criticized by random strangers who lacked the gumption to do what he did in the first place, regardless of any potentially fatal mistakes he might have made in the process.