In mid-April of 1945, as the Nazi empire was dying, a 27-year-old lieutenant named Frank Towers was marching with the 30th Infantry Division in Germany, near Magdeburg.

The 743rd Tank Battalion, attached to the 30th, made the grim discovery of a train filled with 2,500 Jews in different stages of starvation and illness.

Riverdalian Martin Spett was on the train with his family, having survived in the Bergen-Belsen concentration camp for two years. When Mr. Towers, now 93, caught up with the tankers, what he witnessed marked his life.

The soldiers in the tanks told Mr. Towers what they saw when they first encountered the train.

“The stench was so bad, they had to turn around and throw up,” Mr. Towers said in a recent telephone interview from his home in Florida. “The first thing to do, of course, was to give [the survivors] food. They gobbled it up like ravenous beasts. Not being used to a full ration, they immediately threw up.”

Mr. Towers and the rest of the detachment of American soldiers had to perform a kind of triage, he said, separating those who were too far gone to help from those they could. Many of the people on the train suffered from diseases such as typhus and diphtheria.

“We didn’t want to touch them; they were filthy, stinking,” Mr. Towers said. But he and the others who had liberated the train provided medical care and whatever assistance they could.

The Jews who were strong enough were taken to a nearby town, Hillersleben, and turned over to the American military government there, Mr. Towers said. They were stripped of their clothes, which were burned, and paraded into showers, where they were given soap for the first time in many months. While the experience may have been reminiscent of the gas chambers of Auschwitz, the Americans were well-intentioned.

After they washed, the survivors were sprayed with DDT to kill the lice. While the pesticide DDT has since been linked to cancer and other diseases, it was the latest technology at the time, Mr. Towers said.

Local Germans were forced to bring clothing to the Jews, who had been put up in the clean barracks recently used by Nazi soldiers.

“I had to leave them in Hillersleben,” Mr. Towers said. “I needed to finish fighting the war.”