Image Dr. Stephen Melito, a forensic pathology fellow at the Office of the Chief Medical Examiner. Credit... Sam Hodgson for The New York Times

The other fellows have ways of coping, too. Dr. Melito said he did not check the news at home in New Jersey, where he lives with his wife, Mary, a teacher, and their two young children. On hard days, he gets extra hugs.

Dr. Tatsumi said she found herself crying a lot. In an autopsy, she will discover that someone did not die right away and probably felt pain or fear in the final moments. “That just destroys me,” she said. “I’m not very good at hiding things, and so I wear it on my sleeve; I wear it on my face.”

The five medical examiners in training have been invited to stay on. All have accepted except for Dr. Melito, who is taking a job closer to home.

In Dr. Sampson’s office, there are framed photos of every class of fellows on graduation day — the counterpart of the informal collage upstairs in the fellows’ room. Nearly all of these smiling group shots are arranged in neat columns running down one wall. “This side is all Dr. Hirsch,” Dr. Sampson said.

She pointed across the room, where there are just two photos of the last two fellows’ classes. “And that’s my wall,” she said. “Hopefully, it will be long someday.” A photo of Dr. Nunez’s class will soon be added.

Even in medical school, Dr. Nunez said, she was interested in the cause of a disease more than the treatment. A doctor would be poring over a patient’s lab work while “all I’m thinking is, I really wish I could take a piece of this woman’s lung to see what’s happening.”

Dr. Nunez said that she still wanted those answers, but that now her desire was to serve the families left behind. “I think that’s definitely what drew me the most,” she said. “It’s being able to be useful, and bring closure to families, and give them answers that they otherwise weren’t going to have.”