Gilbert Godfrey told the first 9-11 joke just 3 weeks after in NYC!
Although people were rolling on the floor in uncontrolled emotional release they were all yelling "TOO SOON!"

I'm with Spaw regarding the discussion of the appropriatness of humor.
I find people who claim to have a sense of humor, don't.
People who explain why something is funny, aren't.
And defining the rules for humor, isn't worth a dried snot with 23 hairs in it.