In the life of a well respected San Antonio doctor there is a chapter which resonates more powerfully than the rest.
"When the thing went off it was like a canister bomb that penetrated the armor and killed everybody on board," recalls Dr. Michael Kwan as he shares pictures of his days in combat.
The year was 2003.
On the cusp of leaving the military, cardiologist Kwan deployed with the 34th Armored Regiment, 1st Infantry Division.
The place, Habbaniyah, Iraq just west of Fullujah, what many called a "hot zone".
"Me and the other medics would talk and we knew we weren't all coming back and that was a very sobering thought," said Kwan.
As battalion surgeon, Kwan's job was to keep 700 soldiers alive and in the fight.
With combat constant and casualties common, it was not easy.
Kwan recalls clearly the stress and intense challenge of caring for a badly wounded comrade.
"He kept saying, 'Tell Jenna I love her. Tell Jenna love her!', You know that was his wife. I didn't believe it at the time, but I said, Bull shit! You are going to tell her yourself," said Kwan.
And he did. That soldier, Kwan's soldier, survived. But over the course of a year, 17 comrades would not.
For Michael, each loss left a deep, invisible scar he carries to this day.
The first to die was Jason Todd Bryant, a young lieutenant, married a mere month.
"One of the soldiers was told to recover his boots and we couldn't find his boot," said Kwan, his voice choking with emotion.
"His foot was inside the boot. So Jason didn't go home whole and those are the stupid little things that stay with you," said Kwan.
With each day of deployment, each soldier killed in action, Kwan's loyalty and respect embedded more firmly. It was a bond that's remained unbroken by time, distance and death.
"There's not a day that goes by that I don't think about them and the ones that didn't come home. It's hard," said Kwan.
For the lives and dreams cut short by bullets or roadside blasts, Dr. Michael Kwan offers daily tribute - 17 names on a band of steel that's rarely left his wrist.
It is a "HeroBracelet" silently fulfilling an unspoken pledge between those who came home and those who did not.
"Everybody had a fear of dying, but above all else we had a fear of being forgotten," said Kwan.
And in the Kwan home, the obligation of a father is embraced by a son.
"I like to keep them living, just like he does, every single one of his guys," said Ethan Kwan.
For five of his 14 years, Ethan has chosen to wear a HeroBracelet. He claims to feel "incomplete" without it.
"Nobody wants to go out and die for something they love and people they love and not be remembered for it," said Ethan.
And yet for Dr. Kwan the most powerful living memorial to the 17 lost may well lie in the manner he now practices medicine.
The deep bonds built and sometimes broken by war left Michael with a re-newed craving to preserve lives left fragile by failing hearts.
As a transplant cardiologist, he reels recipients back from the brink with the gift of time and a commitment to uninterrupted care in the years they have left.
"You take care of fewer patients, but you take care of the whole patient. So, you get to know them, you get to know their family and stories as well," said Kwan.
An abiding connection, just like with his boys back in Iraq.
As for the 17 who did not survive their memory remains ever present above a healing hand that still serves those who served.
"I think that says a lot of him as a man and a lot of him as a doctor," said Randall Canada, a retired Army veteran and transplant recipient.
A commitment from which Michael Kwan will never retreat.
For him, remembering is gift and duty as one.