Retired NYPD officer John Aris waited for his CT scan results. Seven years earlier, I removed part of his right lung. "No cancer," I told him. He breathed out and settled back. We talked about life, politics, family. Then I asked about the new moment of silence at the 25th anniversary ceremony honoring those who died after Sept. 11 from ground zero illnesses. His smile faded.

He spoke of friends lost not when the towers fell, but years later. Construction workers, firefighters, police officers. Esophageal cancer. Leukemia. Respiratory illness. The funerals never stopped. Beside him sat his wife of 44 years, Kathleen.

Later I saw retired firefighter William Corrar, whom I had operated on for esophageal cancer. Sept. 11 is personal for me. I was a thoracic surgeon at Memorial Sloan Kettering that morning, operating on a patient with asbestos-related cancer. I rode my bike downtown to help. There was little for a surgeon to do.

I skateboarded through the plaza as a kid. Later I delivered for UPS in the South Tower. Now I treat first responders with lung and esophageal cancer, mesothelioma, and other illnesses.