While hunting for material for May Contain Nuts, I often come across stories that are not funny at all, such as:
Bronx Dad Incinerates Teen Daughter’s Body After Strangling
and I'm nevertheless tempted to use it, because I thought of a funny line, a gag, a wisecrack with which to make comedy out of someone else's horrific tragedy.
Luckily, better judgement usually intervenes. But it could go either way.