... which is not to say I am unaware of the valuable, disinfecting concept of 'gallows-humour' so pertinently cited above by Charley Noble; or of that phenomenon whereby 'sanitising, coming·to·terms' jokes inevitably follow some catastrophe [Michael Jackson jokes are probably the most current example, & I expect there were Princess Diana jokes 12 years ago — but, come to think of it, I don't remember any Aberfan jokes, do you? There are some things where even jokes are beyond the pale, perhaps?]...

but but but   ---   a nagging question about taste & moral seemliness will obtrude...