Well as a former photojournalist and newspaper photographer, I can state the following from personal experience.
As a human being, you morally MUST HELP IF
YOU ARE ABLE. However you also must know the realistic limits of what you can do. In this I agree with the post above using the burning house example.
As a personal note, I once arrived at a car crash 5 seconds after it happened. The car, just like in Hollywood, burst into flames from a ruptured fuel tank. Even though I was a paid news photographer, the cameras stayed in my car while myself and another motorist stopped to render assistance. Though conventional First Aid practice is not to move the victim, when the car is engulfed, you really have no choice. We got two out.... one lived and the other (a 19 year old young lady) died in my arms. Even though I have CPR
and military first aid experience, I couldn't do enough. After Fire Dept and EMS people arrived, I got my cameras and did the required shooting for my paper. On a personal level, it took a long time to stop thinking about that day, something you must realize will happen.
If you can't help, then shoot, shoot and keep shooting and record as much documentary information as you can. As an example, think of the 8mm Zapruder film of the assassination of President Kennedy so many years ago. It turned out to be the ONLY documentary evidence of that event. History learned a tremendous amount of that event because one person kept the camera rolling.
I was also once photographing at a parachute school. A woman's chute malfunctioned (roman candle streamer) and I was shooting with a 300mm and a motor drive. I kept shooting thinking to have a great sequence of an emergency chute deployment. She released from the primary chute malfunction, but for reasons never known, the reserve chute did not open and the woman fell to her death. I kept my finger on the motor-drive button till impact. Now that's REALLY not a pretty sight. The photos of this event were published in Newspapers and magazines and wire-services worldwide. But as the photographer, you also depend upon and work with photo editors to keep within the bounds of what should be published, and what should not. Get it all on film. Don't try to self-edit at the time. Just keep shooting. But later, on a frame-by-frame basis you can make the decision what to publish and what not to.
You must also realize that reputable news organizations and magazines have LIMITS on what they will and will not publish. But there are other publications at the bottom of the feeding chain who will offer big bucks to publish the most obscene material. Only YOU can decide what will or will not be used. This is where your moral values will come to play. Greed vs decency. Know your own limits. While some photos of the parachute incident were published, all the photos were supplied and used later at a coroner's inquest into the fatality. This is why it is vitally important NOT to self edit as you shoot. Under pressure and stress of the moment, you really can't weigh the pro's and cons of each individual shot. So shoot now, think and edit later.
As an aside to this discussion, the police tried to confiscate my film of the parachute incident claiming "that I was in material possession of evidence of a fatality". I refused to surrender the film. It is my personal property, and no police officer (in Canada) may confiscate my personal property. However a judge may issue a subpoena and compel me to present this evidence at a judicial enquiry or inquest. I insisted that the officer call his superiors (the film was out of the camera and firmly in the bottom of my pocket) to clarify this. By standing my ground, the officer had to let me keep my film. I later voluntarily supplied whatever prints (WITHOUT CHARGE) were required to the inquest.
So in summary....
Help if you can.
Know your limits.
Never surrender your film.
Thanks for posting such a thought provoking question that makes people think about the morality of what they do.