Resuming media activity after a tragedy: How soon is too soon?

Monday afternoon, tragedy struck Boston.

Following the news that two explosions had gone off near the finish line at the Boston Marathon, everyone seemed interested in what would follow. In a lot of ways, conversation did.

Many took to social media to express their feelings, ask questions or post recent developments in the story.  It seemed to stay like that for awhile, too.

Once I started to see posts and tweets not regarding the situation in Boston, I felt uncomfortable. It felt wrong.

I started to think; when is it too soon to change conversation following a tragedy?