Many years ago, I covered a Baltimore Jewish Council lunch gathering at which the keynote speaker discussed apartheid and how it was affecting South Africa’s Jewish community. After the talk, I grabbed the speaker in the hallway for a moment and asked a few questions, including one about whether he felt a holocaust was imminent in South Africa. Remember, these were the days when Nelson Mandela was still in prison and the white minority ruled.

One older audience member, Chiae Herzig, who was eavesdropping, came up to me afterwards and said, “Excuse me, Alan, but you asked him if there could be a holocaust in South Africa. I don’t mean to butt in, but you need to know that there was only one Holocaust, and to ask if there could ever be another one is incorrect. There could never, ever be another Holocaust.”

Maybe Chiae, God bless her soul, was being a tad reactionary in her comments, but she was right. My usage of the term “Holocaust” was inappropriate. After all, what was going on in South Africa was horrific and terribly wrong, but to compare it to the systematic genocide of European Jewry during World War II was woefully misguided and naive. The Holocaust was and is a singular tragedy unlike any other in the annals of human history.

I feel somewhat similarly about 9/11. The terrorist attacks of Sept. 11, 2001, were also a singular historical event, one that my generation (hopefully) will never, ever forget.

Now I’m a big fan of Wanda Sykes. I think she’s hysterical, and I always enjoy her performances on TV talk shows and “The New Adventures Of Old Christine.” And like many people, I absolutely loathe Rush Limbaugh. His comment earlier this year that he hopes President Obama fails, to me, is tantamount to treason, regardless of your political stripes.

However, to say at last week’s White House Correspondents dinner – even jokingly – that Limbaugh was originally going to be the 20th hijacker on 9/11, “but he was just so strung out on OxyContin [that] he missed his flight,” is just way over the top and way over the line. (Even Sykes herself asked the president from the podium, “Too much?”)

First of all—and I know I say this at the risk of sounding like a wet mop—someone’s past substance abuse problems is nothing to giggle or snicker about. But more importantly, the subject of 9/11 should in every way, shape and form be officially deemed off-limits for even the most extreme, edgy and outrageous comedian.

My guess is that Sykes, as a brilliant, left-leaning entertainer, wanted to one-up and/or woodshed Rush for his “I hope Obama fails” comment. Fair enough. But somehow that needed to be done without alluding in any way to that horrible day in September of 2001.

Some things are just sacred. Like Chiae said to me those many years ago, some things are far beyond comparisons.