It’s the eerie calm that Dr. Louis Harrison remembers most vividly from that day.

As soon as he exited the head and neck tumor board meeting held in the Union Square conference room in Manhattan on 9/11, he learned about the first plane hitting the World Trade Center. Harrison and other members of leadership at Continuum Cancer Centers of New York reported immediately to the command center, activating the organization’s disaster plan.

“Of course we didn’t know it was an act of terrorism right away,” Harrison said. “But we did soon after, when that second plane struck.”

Harrison said he immediately thought about family members who lived in Battery Park and friends who worked in the twin towers.

“I knew so many people affected by that day, I don’t want to put a number on it,” Harrison said. “But I have a cousin who worked in the World Trade Center who by coincidence was scheduled to work in another client office that day. That’s the only person I know from that building who is still alive today.”

But on the morning of the attack, Harrison and his colleagues couldn’t take time to worry about or mourn the potential personal losses. Instead, because Continuum’s anchor medical center, Beth Israel, was the closest academic medical center to the World Trade Center, Harrison and his colleagues prepared for an influx of injured people seeking medical attention.

"My close colleague and I thought we could help in the rescue efforts if they found people in the rubble. The amazing thing was that while we were walking, everyone else was headed in the other direction. "

- Dr. Louis Harrison, Moffitt Radiation Oncology Department Chair, Chief Partnership Officer and Deputy Physician-in-Chief

Every medical professional on-site made themselves available and anxiously awaited the arrival of injured New Yorkers.

“But nothing happened — it was just crickets,” Harrison recalled. “We slowly came to the chilling reality that there was no one coming to the ER. There were no scarred faces or hurt shoulders. That meant there were two categories of people from that day — either you ran out of the buildings or you were dead. There was very little in between.”

Harrison doesn’t remember exactly how long it took for him to realize that he was not going to be treating any injured people at his hospital, but at one point he did want to do something to help. So he and a colleague walked toward the World Trade Center hoping to offer their medical expertise at the site of the country’s worst terrorist attack.

“My close colleague and I thought we could help in the rescue efforts if they found people in the rubble,” Harrison said. “The amazing thing was that while we were walking, everyone else was headed in the other direction. But we were physicians and felt like we could go there to help. We got as close as we could, but the police told us they didn’t need doctors because there just wasn’t anyone alive to take care of. It was just horrible.”

Seeing that he wasn’t able to help, Harrison considered going back to his home in New Jersey. But with the city shut down and transportation lines not operational, he knew that would be impossible. Instead he walked from 14^th to 87^th to spend a restless night at his parents’ apartment. There was nothing else he could do on that terrible day.

“I didn’t get back to my home until the next night,” Harrison said. “Late in the afternoon the following day, we could still see what was left of the World Trade Center burning.”

Like most of the country, Harrison was dazed following the 9/11 attacks. But he continued to work and was back in his office just a few short days later. After all, cancer patients still needed medical care, even after an attack like the one that hit New York City.

But returning to normal was difficult. Not only were more details coming out about the terrorist plot to destroy the United States, but Harrison continued to learn just how close those attacks hit him personally.

The Friday following the events of Sept. 11, Harrison was scheduled to meet with one particular patient whom he was treating for cancer of the nasopharynx. When the patient didn’t show up for his appointment, Harrison decided to call him.

“He and I had really bonded during his treatment, he was a special person and it was unlike him to be a no-show,” Harrison said. “To get his number I had to pull his chart — it was all paper charts back then. That’s when I saw his work address. He worked for a company whose offices were in the World Trade Center, which was headquartered in the top of the North Tower. I saw that and got a chill.”

When he tried the number listed in the chart, a recording kept saying that the phone’s inbox was full.

In all, the company lost 658 employees in the 9/11 attacks. Harrison’s patient was among them.

As each new day dawned, New Yorkers learned about the fate of someone they knew. Photographs lined sidewalks in hopes that someone would have news about a loved one who had not yet emerged from the piles of rubble in the city’s financial district.

Even in Harrison’s neighborhood across the water, the loss of life was substantial.

“There were many children in my neighborhood in Ridgewood, New Jersey, who woke up on Sept. 11, 2001, with two parents and went to bed that night with just one,” he said. “This was not just something unfolding on television. This was very, very real and it still brings tears to my eyes.”

As the days passed, news of heroism and lucky coincidences dotted the string of ongoing news reports on the attack. People who were scheduled to be in the towers that day were delayed for a variety of reasons and survived. Others, like Harrison’s cousin, luckily were reassigned to a different work location on that day.

But one story of pure coincidence stands out the most in Harrison’s mind, mostly because it involved a friend who worked at Beth Israel.

Just like on Sept. 11, there were not many patients coming through the doors of Beth Israel in the days following the attacks. But even without patients, machines still work.

“One of the radiologists asked him if he wanted a PET scan since no one was coming in,” Harrison said. “My friend took him up on the offer and did the scan simply because it was there.”

That decision likely saved his life. The scan identified a life-threatening problem, which was quickly rectified.

“Because of that scan he went and received treatment,” Harrison said. “He’s still alive and doing well today; 9/11 saved his life.”

Dr. Louis Harrison is chair and senior member of the Department of Radiation Oncology, vice president and chief partnerships officer, and deputy physician-in-chief at Moffitt Cancer Center. Before joining Moffitt in 2014, he was physician-in-chief of the Continuum Cancer Centers of New York (now part of Mount Sinai Health System), where he worked during 9/11.