Quote from daniel_m:
and that third option is.......... come on babak, the suspense is killing me!
ok...I'll tell you!
I know some will roll their eyes but this is what I would try to do (keep in mind that I have taken some poetic liscence with the story/scenario that you presented)
I would make the train jump the tracks before it entered either tunnel. Thereby saving both the man and the children in the tunnels.
(this is assuming that this was a cargo and not a passenger train those inside the train, few engineers, would only sustain some injury but probably not death)
ok now go ahead and roll your eyes!! lol
But on a more serious note...there is a reason why I said that there is a third option. Rather than get into a whole rant about why, I'll show you with a famous true story from history:
An army in Tyrol had surrounded the impregnable castle Hochosterwitz and had it under siege. The army was getting restless and the commander had other pressing things to do. Inside, the fortress commandant was faced with the fact that they were down to their last ox and last barrel of barley.
You are the fortress commandant. What would you do? Give up by sending a soldier with a white flag to the enemy encampment to deliver your unconditional surrender?
Or would you ration the remaining food (oxen and barley) and try to hold out till the enemy left or their will/resources ran out?
I'll tell you what really happened after you tell me what you would do. And no sneaking around the net to find out !!

, it is 5 to 1. i WANT to let the man live because he purposely diverted the train so he could do his work. it's the kids who made a bad decision to play there. i suppose you could maybe argue that the man could have put a sign up or something on the other tunnel. anyway, i still think you gotta go with killing the man because it is 5 lives to 1.