I'm generally a pretty stoic guy.
But unexpected scenes or sounds of tragedy make it hard to resist tears.
Pema Chödrön calls this our soft spot.
Most people, feeling this tenderness, build up armor around it, maybe aversion or rejection or numbing themselves, anything to protect it.
She says that if we instead enter the soft spot fully, not trying to change our thoughts or emotions, but hold our pain and the pain of others' in our arms with tender concern, it's a rich opportunity for practice.
Rarely do you viscerally FEEL anothers' pain. In this moment, the self/other wall that is so often built up to shield ourselves is gone.
You can learn a lot about non-existence of this barrier, about equanimity, about compassion, about the need to save others from this samsara...
If only you stay with it
You may find any number of her articles here helpful: http://pemachodronfoundation.org/articles/
For example: http://shambhalasun.com/index.php?optio ... 2&Itemid=0
Please take the above post with a grain of salt.