The gunman didn’t ambush Dr. Jerry Rabinowitz during prayers.

As the shooter stalked his victims in the Tree of Life synagogue in Pittsburgh, Rabinowitz rushed to help the wounded, according to his nephew Avishai Ostrin.

The price Rabinowitz paid for his compassion was his life.

“He was a doctor, a healer,” Ostrin said in a Facebook post Sunday. “When he heard shots he ran outside to try and see if anyone was hurt and needed a doctor.”

He added: “That was Uncle Jerry, that’s just what he did.”

Dr. Jerry Rabinowitz Avishai Ostrin

Rabinowitz, 66, was one of 11 people killed in the mass shooting at the synagogue when authorities say Robert Bowers opened fire during services Saturday. A married couple, two brothers and a 97-year-old woman were also among those who died.

A geriatrician and family physician from Edgewood Borough, Rabinowitz was remembered for his laughter and warmth. He is survived by his wife, Miri; mother, Sally; and brother, Bill.

“You know how they say there are people who just lighten up a room? You know that cliché about people whose laugh is infectious? That was Uncle Jerry,” Ostrin said. “It wasn’t a cliché. It was just his personality. His laughter, with his chest heaving up and down, with a huge smile on his face — that was Uncle Jerry.”

A former patient poured out his grief as well as his appreciation for the doctor who held his hand — literally — during the worst days of his life.

“How I wish I had reached out last year and told him I was ‘making it’ finally, and sent him a picture as proof,” Michael Kerr told NBC News. “You see, I went through many, many dark times.”

Kerr got to know Rabinowitz in the “old days” for those with HIV, before there was an effective treatment for the poorly understood disease that devastated a generation.

“He was the one to go to,” said Kerr, who was Rabinowitz’s patient until he left Pittsburgh for New York in 2004. “He was known in the community for keeping us alive the longest. He often held our hands (without rubber gloves) and always, always hugged us as we left his office.”

Colleagues shared similar memories of the doctor.

Dr. Ken Ciesielka, who went to college and medical school at the University of Pennsylvania with Rabinowitz, said he was “one of the finest people I’ve ever met.”

“He had a moral compass stronger than anyone I have ever known,” Ciesielka told the Pittsburgh Post-Gazette.

Augie Siriano, a caretaker at Tree of Life, remembered other victims he considered friends or even family.

Sylvan Simon, 86, and his wife, Bernice, 84, “were just the nicest people,” he told NBC News affiliate WPXI.

And siblings David and Cecil Rosenthal were “like brothers to me,” Siriano said.

“I was tying Cecil’s shoes and stuff because it was kind of hard for him,” the caretaker added.

An organization that provides residential and employment services to people with disabilities said in a statement it was “devastated at the loss” of the Rosenthal brothers.

David and Cecil Rosenthal (right), victims of a shooting at a synagogue in Pittsburgh.

“Cecil and David had a love for life and for those around them,” the ACHIEVA statement said. “Our collective hearts are heavy with sympathy.”

Richard Gottfried, another of the 11 victims, was a dentist who volunteered his services with Catholic Charities.

The 65-yer-old known to many as "Dr. Rich" was Debi Salvin's twin, and Bonni Huffman's "baby brother."

"Growing up, he as the only boy, he had three sisters that he had to deal with," Salvin said on "Today." "It’s just unimaginable that somebody that was so full of life is gone in an instant."