cold-hearted?

Someone I used to work with died today. She wasn't very old and was pregnant with her second child. She and her husband had traveled across the country to attend his father's funeral when an aneurysm was detected in her brain, the pregnancy failed, and she died within about 24 hours. These are tragic and terrible things to have happen to anyone, especially to a young family like theirs.

Many people around me are very upset by this and I do not begrudge them that. Many of them knew her far better than I or are more capable of seeing themselves in this tragedy, I presume. I don't intend to seem unfeeling or uncaring, but I find it hard to muster up much of an emotional response.

I guess I feel and experience things differently than many. I knew and liked these people, but I didn't know them well and had never spoken to either outside the context of work (nor had I done so in several years). Surely knowing that we weren't that close on the monkeysphere excuses me from getting too upset, right?

Every time that devastation occurs, there are people who personalize things that aren't truly personal - if this woman had died in an era before Facebook, I probably never would have learned of her death and neither would a number of the others who are eulogizing her at present. The fact that I do know seems not to provoke a strong emotional response in me, though, despite the fact that so many others are broken up by this. I get upset and emotionally involved when things happen to those who are truly close to me, but I really don't have it in me to take this specific event personally.

I know that there have been people to call me unemotional or cold-hearted or similar things, but I resist those labels. Surely there is some positive (or at least neutral) label that can be given to people who are simply less likely to get emotionally-involved in the troubles of others. Isn't there?