Everyone remembers where they were on 9/11.
I was at Bellevue Hospital, in the emergency room, where we cleared out almost the entire hospital for the only time in my memory.
We prepared for survivors of the World Trade Center disaster and set up a system of triage for how we would take care of the sickest and most injured patients first.
Our surgeons were at the ready, as were our ICU teams.
And we waited.
The survivors we were expecting never came because there were so few, as I wrote the next day for The Post.
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, becoming the first certified fatality of the terrorist attacks.
He was a Franciscan friar, Catholic priest and Fire Departyment chaplain, a loving, kind man who never had a negative word to say about anyone.
Since he was gone, another FDNY chaplain and patient of mine, Monsignor John Delendick, presided over the funerals of the firemen who died in the attacks.
Father John was nowhere near as eloquent, but he was and is a man of great 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 wore an N95 mask.
Many wore them but many didn’t, and there was no awareness at this time there would be such severe health consequences, with people to suffer various kinds of cancer from lung to blood cancers 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 conditions to all responders and survivors through 2090.
There are more than 69,000 WTC responders, and it is clear to me and other physicians who treat various conditions arising from 9/11 exposure that there are many more health issues than are currently identified.
All due to the burning ash, products of combustion, particulate matter, silicon, asbestos, metals, concrete, glass and other chemicals in the air.
Health problems also include anxiety, depression and post-traumatic stress, all prominent effects of WTC exposure in responders, survivors and those who lost loved ones.
The country was lost in the days that followed, until Sept. 14, when President George W. Bush stood on that car hood amidst the World Trade Center rubble at Ground Zero beside a retired firefighter and called out through a bullhorn, “I can hear you! The rest of the world hears you. And the people who knocked these buildings down will hear all of us soon.”
This was the American way, courage in the face of sudden adversity, standing up against our foes. It became a galvanizing moment for Bush and for America.
A decade later, after he left the White House, I got to know the former commander in chief, to interview him several times, to ride mountain bikes with him and wounded veterans and found him to be that kind of effective leader in person too.
The veterans of the Iraq and Afghanistan campaigns who know him can attest to the power of his personal leadership, especially important to remember at such a divisive and confusing time as right now.
9/11 hurt us but also made us proud to be Americans, a healthy outcome to a sick 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 Fox News medical analyst.