I think humour is a personal thing. The 'sick jokes' that pop up, predictably, after an event, usually annoy and sicken me and I delete them.
But it has to be said that a lot of humour concerns things that aren't actually funny (in reality) yet we laugh. Firemen and Policemen see terrible things on a regular basis ans have a long list of black humour type jokes. Its a way of coping.
Humour is a funny thing.....