There's been a bit of controversy in the news regarding an incident in New York. Basically, a man was pushed in front of a subway train, and subsequently died. Another man was on the platform, and he took photos of the incident: one of these photos subsequently appeared on the front page of the New York Post. Some people are criticising the photographer for taking pictures rather than doing anything to help; he claims that he was too far away to do anything, and that he was just trying to use his flash to attract the train driver's attention (i.e. the photos were accidental). For more info, see the BBC, The Guardian, or The Daily Mail. (The Mail seem to have taken the strongest position of moral outrage against the photographer, while also including a video of the incident on their website.)
I wasn't there, and I don't know any of the people concerned. I also understand that if you make a decision in a rush, you might think of something better later. So, I'll give the photographer the benefit of the doubt, and assume that he's telling the truth. That said, I don't recommend following his strategy if you ever wind up in a similar situation.
Transport for London have a guide to filming and photography, which explicitly says: "Flash photography or additional lighting is not permitted on any platform." As I understand it, that's for safety. If the train has just come out of a dark tunnel, then someone uses a camera flash, the driver will be temporarily blinded. So, in a case like this, that would make it harder for the driver to see the person on the track ahead. I think it would be better to find an alarm on the platform, if only to call the emergency services after the collision.
