Among the thousands of commuters traveling through Pennsylvania Station late last month was Kurt Salzinger, a native of Austria who fled the country as the Nazis marched in. He distinguished himself years later in the United States as a scholar in the field of behavioral psychology.

Dr. Salzinger, 89, and his wife were on their way to Macy’s Herald Square on Oct. 27, when a hurried straphanger rushed past them on a subway platform in Penn Station, the police said. The man shoved the couple out of his path with an arm that knocked them both to the ground, Mr. Salzinger’s family and the police said, before disappearing on a southbound 3 train headed to Brooklyn.

Strangers rushed to help Dr. Salzinger, who was lying helpless on the platform. He was hospitalized with bleeding of the brain from the fall, and later contracted pneumonia, his relatives said. He died on Thursday.

The police and Mr. Salzinger’s family believe his death was an accident, but they are awaiting an official determination from the medical examiner. The encounter was not captured on video, and the police have not yet located the straphanger to interview.