Everyone remembers where they were on 9/11.
I was in the emergency room at Bellevue Hospital where, for the only time in my memory, we cleared out almost the entire hospital.
We prepared for the survivors of the World Trade Center disaster and established a triage system that envisioned how we would care for the sickest and most injured patients first.
Our surgeons were ready, as were our intensive care teams.
And we waited.
The survivors we expected never came because they were so few, as I wrote for The Post the next day.
I remember when I first heard that my patient and dear friend Father Mychal Judge had died trying to rescue people from the burning buildings, making him the first confirmed fatality of the terrorist attacks.
He was a Franciscan monk, Catholic priest and fire department chaplain, a loving, kind man who never said a negative word about anyone.
Since his death, another FDNY chaplain and patient of mine, Monsignor John Delendick, has led the funerals of the firefighters who died in the attacks.
Father John was not nearly as eloquent, but he was and is a man with a big heart, which he showed in the days to come.
A few days after the attacks, I went to the World Trade Center site to examine the rubble. I noticed all the smoke in the air and was wearing an N95 mask.
Many wore them, but many did not, and at the time it was not realized that this would have such serious health consequences that people would suffer from various types of cancer, from lung to blood cancer to melanoma, thyroid and prostate cancer.
In 2011, the Centers for Disease Control and Prevention launched the World Trade Center Health Program, a commitment to provide free medical care for 9/11-related illnesses to all responders and survivors by 2090.
There are more than 69,000 WTC responders, and it is clear to me and other physicians treating various medical conditions resulting from the 9/11 contagion that there are many more health problems than are currently being identified.
All due to the burning ash, combustion products, particulate matter, silicon, asbestos, metals, concrete, glass and other chemicals in the air.
Health problems also include anxiety, depression and post-traumatic stress, all important effects of WTC exposure among responders, survivors and those who have lost loved ones.
The country was lost in the days that followed, until on September 14, President George W. Bush stood on the hood of his car amid the rubble of the World Trade Center at Ground Zero next to a retired firefighter and shouted through a megaphone: “I can hear it .” You! The rest of the world hears you. And the people who tore down these buildings will hear from all of us soon.”
This was the American way of being courageous in the face of sudden adversity and standing up to our enemies. It was an exciting moment for Bush and for America.
A decade later, after he left the White House, I got to know the former commander in chief, interviewed him several times, mountain biked with him and wounded veterans, and witnessed him being such an effective leader in person.
The veterans of the Iraq and Afghanistan campaigns who know him can attest to the power of his personal leadership, which is especially important in a time as divisive and confusing as this one.
September 11th hurt us, but it also made us proud to be Americans – a healthy result of a nasty attack.
We can still learn from it.
Marc Siegel, MD, is a clinical professor of medicine and medical director of Doctor Radio at NYU Langone Health and a medical analyst on Fox News.