I can only imagine how, I suppose to a similar extent, my paternal grandfather's father and living siblings felt on September 11, 1922 and subsequent days. From what I understand, my great-great-granddad Julian Czarnecki was absolutely no hero—or if he was one, his bad facets outweighed his good ones. Nonetheless, his death must've really weighed on my great-granddad and his living siblings (one of whom would follow her father only slightly over 2.75 years later).
Great-Granddad was going to be 18 that October (and to compound the worst matters in his life, he turned 25 on a day on which a 25th birthday would not be joyous to anyone—Black Thursday). So on that birthday (and subsequent birthdays), he had to remember the loss of his father (with whom he had a conflicted relationship—or at least I'd be surprised if he didn't have a conflicted relationship with him—and subsequent birthdays would become even worse as the years passed and worse events kept happening—in fact, his 35th birthday had the fresh pain of Black Thursday's 10th anniversary and the only-almost-two-months old invasion of Poland).
As for Great-Granddad's youngest sibling, she wasn't yet even nine months old when Great-Great-Granddad died—and the oldest surviving one had, if you count 13 as the bat-mitzvah age, become a bat-mitzvah that year (and she was the one whom followed Great-Great-Granddad into death on June 23, 1925).
At least none of them were around to see 9/11. However, my great-granddad's widow—to whom he was quite abusive, and with whom she obviously had a conflicted relationship—was, and so were four of his five children (One died seven hours after birth, right before the 10th anniversary of his aunt Regina's death.). While I do not know whether my great-grandma ever met her father-in-law or her sister-in-law Regina, I know that she was well aware that September 11th always carried pain for my great-granddad—as carried every October 24th, and not just because of the September 11th before his 18th birthday—and both were born in Jewish homes (he in Anti-Semitic Polish Russia, she in an Anusi home in Ashley-Hanover Township, Pennsylvania) and raised in Anusi homes, and they thus knew the pain of every passing September 11th (on which Great-Great-Granddad may not have died had his family not disowned him for becoming an Anusi) and October 24th.
I can only imagine how the pain of every other September 11th hit her on 9/11, and I never did ask her because I didn't know our family story—not even that we were and are Jews—not to mention that I saw her only once every year from some time in the 90s until 2005, and I was dealing with an abusive dad (It's like the Passover question that the fourth child doesn't ask—he or she doesn't ask because he or she doesn't know how to ask or maybe even to ask at all.).
I wonder what she thought—or at least would've thought—if she heard this song—I also wonder the same about Pop-Pop (whom was sadly, as Granduncle Tony stated, "Like father, like son.") and Granduncle Tony (whom unexpectedly died on July 31 2014, three days after what would've been his mother's 101st birthday). I also certainly wonder what Great-Granddad would've thought and what Granduncle Red (Francis "Red" Czarnecki, whom died in 1985) would've thought (BTW, he was called "Red" because of his red hair—which, as I later found out, is, so to speak, a dead giveaway of if someone is Jewish in Poland, as is Brown hair for someone whom's a Brown-haired Jew, as Ethnic Poles are indigenously light-haired and light-eyed).