There was a man, maybe 5-foot-3, well coifed in a white shirt and suit jacket. She noticed him immediately, but not in time. He jumped.

The next moment, the man’s contact with the electrified rail was all she would be able to imagine when she went to bed over the next six months. She said she was unable to sleep for more than two hours at a time.

“I was always seeing it, you know?” Ms. Moore, 45, from Staten Island, said. “I see him alive and….”

In the last month, the cases of two men who were pushed to their deaths on the tracks have focused attention on the subway system’s most harrowing outcome. But for the men and women who operate New York City’s trains, these episodes represent an occasion to induct two new people to a grim fraternity with hundreds of members. With dozens of people jumping and falling to their deaths on the tracks every year, any of the five million passengers who ride the city’s subway every day can reasonably expect to be driven by someone who has seen, heard or even felt someone perish right in front of them.