When Justin Zemser didn’t call Tuesday night, his family started to worry.

He was on the Amtrak train headed home to Rockaway Beach, N.Y. when it derailed, and his family knew that Zemser, a midshipman at the U.S. Naval Academy who had been valedictorian of his high school class, would let them know he was okay. If he possibly could.

“He was just such a nice, good boy,” his aunt Cathy Zemser said in an interview with The Washington Post. He liked the discipline of football, the discipline of classes, the discipline of the Naval Academy. “He was very, very responsible. We knew it wasn’t good if he hadn’t called.”

His uncle, Richard Zemser, called hospitals over and over — more than 200 people were injured in the accident, so patients kept arriving. He called police, the Naval Academy, more hospitals.

On Wednesday morning he and his wife learned that Justin Zemser was one of the seven people who died in the crash.

“This just shouldn’t happen,” Richard Zemser said, struggling for composure. “This wonderful, wonderful kid.”

Zemser, 20, of Rockaway Beach, N.Y., was a sophomore at the Naval Academy in Annapolis, Md. He was on leave and headed home when the Amtrak train derailed in north Philadelphia about 9:30 p.m. He had just been home to visit family for Mother’s Day.

“I speak for the entire brigade of midshipmen, faculty and staff in saying we are completely heartbroken by this,” said Cmdr. John Schofield, a spokesman for the U.S. Naval Academy. The Naval Academy won’t be releasing any more details until Thursday, he said, out of respect for the family and the brigade, who were notified of the death Wednesday morning.

“The Naval Academy is supporting the midshipman’s family, friends, and loved ones during this time of grief,” the academy said in a statement. “Grief counseling services and support are available to midshipmen, faculty and staff through chains of command, our chaplains, and the Midshipmen Development Center.”

Howard Zemser, Justin’s father, asked Wednesday for more time with family before talking publicly about his only child.

But Richard and Cathy Zemser warmly described their nephew, whom Richard Zemser would tease when he called: “Am I talking to the first Jewish president of the United States?”

They would both laugh, but Richard Zemser said he was serious, too – there was something about the way his nephew would set his mind to something, and make it happen. At 5-foot-8, he was co-captain of his high school football team. He was president of the student council at Channel View School for Research. He was valedictorian. And, though he would be the first in his immediate family to go to college, he was determined to go to the Naval Academy.

He wanted to be an elite Navy Seal.

Cathy Zemser remembered leaving him in Annapolis, in his shorts and flip-flops, and returning a few hours later to see him lined up with all the others in his Navy whites.

He played on the academy’s sprint football team, a varsity sport limited to players who weigh 172 pounds or less, as a wide receiver. He was curious. He loved to read, especially books about history. He got excited about small adventures; his uncle would say, “Where are we going to go today?” and they would end up at the American Museum of Natural History, or Coney Island, riding the front car in the Cyclone.

Justin Zemser had just turned 20. He had just taken, with a few others from the academy, his first trip to Israel. In a video posted on youtube of the Friends of the Jewish Chapel at the Naval Academy spring break trip, midshipmen are seen joyfully exploring Israel, splashing in waterfalls, stepping through ancient stone arches, spreading Dead Sea mud on themselves, singing by firelight.

Zemser had just switched majors from engineering to English. He had just finished a course he loved: The Bible and Literature. Earlier this month, he wrote a long, thoughtful letter to his uncle, that read, in part:

“In all that we have talked about over the years regarding God, religion, and our place in the grand scheme of things, I now come to you with even more questions. After taking this course, and opening my eyes to a spiritual world well beyond anything I have ever experienced, my mind is jumbled. Where do I fit in all of this? The more I have read the Old Testament, the more I began to understand our roots, our ancestry, and the belief system that is, perhaps, engrained in our blood. I saw an intriguing God, one with great personality, wisdom, and compassion, but also with a variety of flaws and questionable judgments. Questioning God and his motives made him much more relatable, and in weird sense, much more human. And at the same time, I have read about a man in the New Testament, one that built relationships, and loved unconditionally. Where do I go with this?”

He was trying to understand, Richard Zemser said: “He was looking for solutions to whatever exists today in the world.”

“It’s tragic when anybody dies, anybody that you love,” Cathy Zemser said by phone, looking at a photo of her nephew when he was a 4-year-old. “But for a young boy with a brilliant future ahead – it’s just …

“It is the most devastating thing.”

Jennifer Jenkins contributed to this report.