There are times in life when you're on the outside of a terrible situation, with no reasonable way to make a difference. It may not impact you in any significant way, but that doesn't stop the feeling of wanting to help. You'd like to do something, anything that will improve things, but you just don't have any options...you're helpless.
These helpless situations make me sad and angry. Sad for the people who have to deal with whatever is going wrong, and angry at my own inability to affect the situation. To the point of tears, sometimes, especially if I know the people involved. And that in turn makes me feel a bit guilty. I don't really have any skin in the game, so who am I to be feeling poorly about a situation that doesn't affect me? Knowing that doesn't help, unfortunately.
Distracting myself from the situation is one option, and it actually works pretty well in truly remote cases. Wars or terrorism that is going on halfway around the world, for instance. The helpless feeling is there, but only briefly. Once the next news story comes up, or I start doing something unrelated, I can put it out of my mind. Unfortunately, distraction doesn't work nearly as well when I'm close to the situation, usually because I know someone involved.
Sometimes, I'm able to redirect the energy from the sad/angry/helpless feelings into productive outlets. This blog, for instance (though "productive" is questionable there). Or the occasional volunteer work that I participate in. I can't affect the original situation through whatever I'm doing, but I'm helping someone, and that certainly counteracts the negative feelings.
Another coping mechanism is prayer. You see some variation of the "thoughts and prayers with you" phrase more often than just about anything else in response to someone having a difficult time. I suspect I may not be particularly popular among other believers (in almost any faith) for my viewpoint on this, but prayer just doesn't help me with the feelings of helplessness. My faith as an evangelical Christian certainly tells me that prayer is important, and I do pray regularly for all kinds of things, including these helpless feeling situations. It doesn't help me feel better, though, because logic tells me that an omniscient, omnipotent, loving God already has done everything that He feels is appropriate regardless of what I have to say. I do believe He still listens - otherwise I wouldn't pray at all - but it just doesn't give me any relief from that helpless feeling.
In the end, though, what helps most in these situations is this: in the act of sharing, some portion of the emotional load is lifted from the person who is suffering. I first came across the saying "shared pain is lessened; shared joy, increased" in a Spider Robinson novel long ago, and I'm sure he wasn't the first to express that sentiment. Over the years, I've found that saying to be true on both counts. The closer you are to the other people involved, the more it applies. The feeling of helplessness is much lessened when I remember that simply sharing these difficult situations benefits those involved.