While working on a report about 9/11 for her class at school, my 9-year-old daughter said something poignant.

“I wish 9/11 never happened so that Mr. Beau’s brothers would still be alive,” she said.

“Mr. Beau” is my friend and co-author, Beau Wise. He is not only a U.S. Marine combat veteran, but the lone American service member to be pulled from the battlefield since 9/11 as a result of the war in Afghanistan. Beau lost both his brothers, U.S. Navy SEAL and CIA hero Jeremy Wise and U.S. Army Green Beret Ben Wise, in a war that continues 19 years after the terrorist attacks of September 11, 2001.

U.S. Marine combat veteran Beau Wise visits the graves of his two brothers, U.S. Navy SEAL Jeremy Wise and U.S. Army Green Beret Ben Wise, at the Alfred G. Horton Memorial Veterans Cemetery in Suffolk, Virginia, in June 2019.

On 9/11, 2,977 innocent people in the World Trade Center, Pentagon and four hijacked planes were murdered by radical Islamic terrorists. In the nearly two decades since, more than 7,000 U.S. military heroes have died in war. Countless families, including the Wises, have been forever altered by the events of one terrible day.

In our forthcoming book, Beau recounts first hearing about the 9/11 attacks while sitting in class at his high school in Hope, Arkansas. His thoughts immediately shifted to Ben, who had already enlisted in the U.S. Army. In the coming months, their older brother Jeremy would leave medical school to begin Navy SEAL training. Beau joined the Marine Corps a few years later and would deploy twice to Afghanistan.

Jeremy was killed in a sneak attack by al Qaeda in 2009, while Ben was fatally shot in a fierce firefight with the Taliban just over two years later. Despite desperately wanting to return to Afghanistan, Beau was barred from further combat service by the same Pentagon policy that inspired the movie Saving Private Ryan.

In more than a decade of connecting with veterans like Beau and Gold Star families like the Wises, almost every American hero’s decision to serve their country can be traced to 9/11 if they were old enough to remember the attacks. Like Pearl Harbor, 9/11 was the call to arms for a generation of warriors whose fire still burns no matter how many years go by.

The 9/11 tribute in light is astounding. They tested it last night.
Never forget. pic.twitter.com/NimAzfPzf9

— Bryan Llenas (@BryanLlenas) September 5, 2020

Like the heroes who would defend America after the attacks, Rick Rescorla served his nation in battle. As head of security at Morgan Stanley on September 11, 2001, Rescorla sprung to action as soon as the first hijacked airliner hit the World Trade Center’s North Tower. While gently singing through a bullhorn to calm frightened employees, he helped evacuate thousands from the South Tower before bravely returning to assist others.

“He wasn’t thinking about himself after that first plane hit,” Rick’s wife, Susan, told me in 2011.  “He did what he did in Vietnam: leave no man behind.”

Rick Rescorla died when the South Tower collapsed. President Trump posthumously awarded the Presidential Citizens Medal to the fallen hero last year.

Thank you for a wonderful evening. @tthrash @59NationalParks #parkchat And everyone who participated!

Join us virtually on Friday September 11, 2020 at 9:45 am for the 19th observance via @EarthCam and @FriendsFlight93: https://t.co/QZaaDXVFNV pic.twitter.com/Nfwdxl2ZYr

— Flight 93 NMEM (@Flight93NPS) September 10, 2020

Todd Beamer didn’t serve in the military, but his battle cry aboard United Flight 93 – “let’s roll” – would inspire countless soldiers, sailors, airmen and Marines who subsequently deployed to Afghanistan, Iraq and other post-9/11 battlefields. Some military units even adopted “let’s roll” as an unofficial slogan.

Beamer and his fellow passengers won the first battle of the war on terrorism by courageously confronting their attackers and making the ultimate sacrifice while forcing the hijacked plane off its murderous path to our nation’s capital. “Let’s roll” will forever be a symbol of not only Flight 93, but an entire generation’s courage on and after 9/11.

BREATHTAKING: The night sky over the Pentagon is lit up by the Tunnel to Towers Foundation over the Pentagon in remembrance of 9/11.

MORE: https://t.co/n0q6FyOSy7 pic.twitter.com/7grdsDA0T2

— ABC 7 News – WJLA (@ABC7News) September 10, 2020

U.S. Army Lt. Col. Ted Anderson was one of the heroes of the terrorist attack on the Pentagon. According to an Army account published in 2008, Lt. Col. Anderson had already carried two injured employees out of the burning building when he ran back inside and found two more victims, including one who was on fire. He then “tackled the employee and rolled him on the ground to extinguish the flames.”

After getting the burn victim to safety, Anderson had to be restrained from going back into the smoke-filled corridor by firefighters.

“You don’t leave your comrades on the battlefield,” Lt. Col. Anderson said in 2008. “To me, this was the battlefield.”

As my daughter continued working on her class report about 9/11, I tried to explain the meaning of selfless sacrifice.

“The heroes who ran into those burning buildings would probably do it again,” I said. “And so would Mr. Beau’s brothers.”

This and every 9/11 anniversary is an opportunity to remember and reflect. 9/11 also gives us a unique chance to teach our children about sacrifice, patriotism and unity. During these troubling times, perhaps looking back on a day that truly changed the world – and how countless heroes responded in the 19 years since – can help us conquer a pandemic and heal a deepening national divide.

Let’s roll.

Tom Sileo is a contributing senior editor of The Stream. He is co-author of Three Wise Men, Brothers Forever, 8 Seconds of Courage and Fire in My Eyes. Follow Tom on Twitter @TSileo and The Stream at @Streamdotorg.