“9/11 jokes always fall flat”

Jokes about the September 11, 2001 terrorist attacks on New York City’s World Trade Center are numerous, although not politically correct. One popular joke was posted on Twitter on February 6, 2013:
   
“9/11 jokes always fall flat.”
     
Sometimes it’s two jokes that fall flat, like the Twin Towers (World Trade Center). “‘I would make jokes about 9/11, but the two I know always fall flat’ - Chris Ray Gun” was posted on Twitter on July 26, 2016.
   
 
Wikipedia: September 11 attacks
The September 11 attacks (also referred to as 9/11) were a series of four coordinated terrorist attacks by the Islamic terrorist group Al-Qaeda on the United States on the morning of Tuesday, September 11, 2001. The attacks consisted of suicide attacks used to target symbolic U.S. landmarks.
 
Four passenger airliners—which all departed from airports on the U.S. East Coast bound for California—were hijacked by 19 al-Qaeda terrorists to be flown into buildings. Two of the planes, American Airlines Flight 11 and United Airlines Flight 175, were crashed into the North and South towers, respectively, of the World Trade Center complex in New York City. Within an hour and 42 minutes, both 110-story towers collapsed, with debris and the resulting fires causing partial or complete collapse of all other buildings in the World Trade Center complex, including the 47-story 7 World Trade Center tower, as well as significant damage to ten other large surrounding structures.
 
Twitter
St. Bencent‏
@detrituz_
9/11 jokes always fall flat.
11:19 PM - 6 Feb 2013
 
Twitter
Pickupliness‏
@Pickupliness9
No 9/11 jokes they always FALL flat but
Boston jokes are the bomb
8:56 PM - 2 May 2013
 
Twitter
Charlie Wilson‏
@cinestercharlie
I don’t have any funny 9/11 jokes.  Every time I tell a 9/11 joke they always fall flat.
12:57 AM - 4 Apr 2016
 
Twitter
Pandorazerstörer‏
@Ohmwrecker_
“I would make jokes about 9/11, but the two I know always fall flat” - Chris Ray Gun
2:09 PM - 26 Jul 2016
 
Twitter
capn’ toaster bitch‏
@plzpancakenbutt
Replying to @GrooveSDC
I’d tell two of my 9/11 jokes but they always fall flat
12:37 PM - 18 Aug 2016
 
Reddit—Jokes
Aetherbot March 21, 2017
9/11 jokes always fall flat.
 
Twitter
Miku Baruah‏
@MikuBaruah
I kinda only know 2 jokes about 9/11 but they always fall flat.
3:29 PM - 26 Mar 2017
 
Reddit—Jokes
I Keep Trying To Tell 9/11 Jokes,
submitted May 7, 2017 by dawgfan24348
but they always fall flat.