All the while, he was raising his son as a single father and caring for his mother, who eventually moved in with him in Brooklyn. He talked openly to his teenage students about his impoverished childhood.

“He was the pillar of our family, he was the glue of our family, he was the motivator, everything,” said Treinna Griffith-Johnson, a cousin. When it came to his students, “He knew what a struggle was — and if he could do it, so could they.”

At home in New York on Tuesday night, Cynthia and Richard Finamore spent a frantic night calling Philadelphia-area hospitals, looking in vain for their daughter, Laura Finamore, 47, a managing director at Cushman & Wakefield who was heading back to Manhattan.

“Laura’s smile could light up a room, and her infectious laughter will be remembered by many for years to come,” her family wrote in a statement released on Thursday. “She was always there when you needed her — with a hug, encouraging words or a pat on the back.”

A George Washington University graduate who grew up in Douglaston, Queens, Ms. Finamore had spent 20 years in commercial real estate, joining Cushman & Wakefield in 2008. But her “favorite role,” her family said, was as an aunt to seven nieces and nephews.

Giuseppe Piras was from the Sardinian town of Ittiri, and had traveled to the United States to promote his family’s olive oil, according to the Sardinian newspaper La Nuova Sardegna. He had also begun to export wine.

Mr. Piras left Italy for the United States on Monday morning, an uncle said in a video on the newspaper’s website, and had planned to stay for a week. He called his father shortly before boarding the train to say that he would call later because he was in a hurry.