David and Cecil Rosenthal, brothers in their 50s, were almost always in the synagogue, greeting everyone who came with a “Good Shabbos” and a ready prayer book. Joyce Fienberg, 75, prayed there every day after her husband’s death. And Melvin Wax, 87, took on so many tasks — from leading services to changing light bulbs — that one friend described his role there as “everything but the cantor.”

The shooting rampage at the Tree of Life synagogue left 11 people dead, including the Rosenthal brothers, Ms. Fienberg and Mr. Wax. Many of those who perished were advanced in years. Some, like Rose Mallinger, who was 97, were alive while the Holocaust was devastating Jewish communities around Europe. They were the steady anchors of a faith community that had changed over the years but persisted as a source of devotion, camaraderie and memory.

“The people who were there are the ones who kept this community going, who made things happen,” said Diane Rosenthal, a sister of the Rosenthal brothers. “I imagine they probably greeted this guy. This place was so part of their lives, a place where they could go and be welcomed at any time and where they were part of the fabric.”

The dead included three women and eight men ranging in age from 54 to 97. Among them were an accountant, a teacher, a dentist and a husband and wife, Bernice and Sylvan Simon of Wilkinsburg, Pa., who were 84 and 86.

Daniel Stein, 71, had recently become a grandfather. Jerry Rabinowitz was a doctor and lived in the town of Edgewood Borough, and Irving Younger, 69, in Mt. Washington.

Everyone with ties to Tree of Life knew the Rosenthal brothers, who turned up every week and always stood at the back.

“They’ve been fixtures there for as long as anyone can remember,” said Jeffrey Solomon, the chief executive of Cowen Inc., a New York-based financial services company, and a lifelong member of the Tree of Life congregation. “They were what we call ‘shomerim,’ people who guard the religion even for the rest of us who don’t go all the time,” said Mr. Solomon, who is related to the brothers by marriage.

David Rosenthal, who was 54, and Cecil Rosenthal, 59, had developmental disabilities but lived independently. They often spent their days at the nearby Jewish Community Center, where they spoke warmly to anyone they met.

“I’ve said this many times, having nothing to do with this tragedy: You can feel what is good in the world when you talk to them, because they only talk to you about good things,” Mr. Solomon said. “To say that everyone in the Pittsburgh Jewish community knows them is not even a remote exaggeration. They were both active participants in so much of life.”

Image Melvin Wax.

Mr. Solomon said he grew up in the community with the brothers, who were together constantly and often spoke joyfully about their extended family.

“Today we talk about inclusion, but they were just part of the community, and I didn’t think anything about it," Mr. Solomon said. “It was my introduction to the fact that there are people like that and they are just like the rest of us.”

“It doesn’t make any sense to me," he added. "They didn’t deserve this.”

Another victim, Richard Gottfried, 65, of Ross Township, Pa., was remembered as a loyal congregant and a dentist who would serve patients who did not have insurance or were underinsured, performing root canals, installing crowns on teeth and doing other preventive and restorative work.

“He was very devoted to community and to service,” said Susan Kalson, 59, the chief executive of the Squirrel Hill Health Center. “He loved working with our patients, underserved patients, including a lot of refugees and immigrants.”

Dr. Gottfried, described as a quiet, kind and unassuming man, was a dentist in the Pittsburgh area for decades after starting a private practice with his wife, also a dentist, in 1984. Seven years ago, he was looking for a way to give back to the community, and started working about once a week at the Squirrel Hill center, where he found a way to “do for others,” Ms. Kalson said.

She said Dr. Gottfried was deeply devoted to Judaism. He and his wife, who was not Jewish, both worked part time at the center and were very close. They had no children, Ms. Kalson said, adding, “They were just one of those couples that is just so interwoven.”

Another victim, Daniel Stein, was a jack-of-all-trades, said his nephew, Steven Halle. Mr. Stein was a substitute teacher, who over the years had also worked at a plumbing supply store and a funeral home.

But the place where Mr. Stein, 71, spent most of his time in recent years was at the synagogue, Mr. Halle said.

On almost every Saturday morning, he attended services. Sometimes he went with his wife, Sharyn, but on Saturday, he went alone.

“It was like clockwork, for years and years,” said Mr. Halle. “He didn’t miss it for anything. The synagogue was his life.”

Image Daniel Stein.

His congregation, the New Light Congregation, had moved into the Tree of Life synagogue about two years ago because their numbers had dwindled and they could no longer afford their own building, Mr. Halle said.

Mr. Stein’s daughter-in-law recently had a child, and Mr. Stein was delighted to be a grandfather for the first time.

“This is going to be a horrible loss for the child — growing up without a grandfather,” he said.

Although he enjoyed traveling — he had taken a Caribbean cruise with his wife and had also visited Israel — Mr. Stein was usually not away for too long from Pittsburgh. He died within a few miles of where he was born, Mr. Halle said.

Ms. Fienberg was also known for her warmth and generosity. In the more than 40 years that Dodie Roskies knew her, she would come to count herself as one of Ms. Fienberg’s many best friends.

During that time, she would also come to know how, after the death in 2016 of Ms. Fienberg’s husband, Stephen E. Fienberg, who was a pre-eminent statistician at Carnegie Mellon University, Ms. Fienberg would go every day to the synagogue to pray for him.

“She was a wonderful wife, mother and grandmother,” said Ms. Roskies, the director of a genetic education and screening program for Jews whose families came from Central and Eastern Europe.

Ms. Fienberg raised her family in Squirrel Hill, Ms. Roskies said. Ms. Fienberg has two sons, one living in Washington and one in Paris, and six grandchildren.

Ms. Fienberg was bright, charitable and devoted, Ms. Roskies said. She worked for years at the University of Pittsburgh’s Learning Research and Development Center.

“She was the gentlest of people,” Ms. Roskies said.

Mr. Wax, another victim, was often at the synagogue three or four days a week, performing even the smallest tasks to ensure things went smoothly.

“He was part of the fabric,” said Bill Cartiff, 56, one of his friends.

As he aged, Mr. Wax had become hard of hearing, and in recent years, he did not speak much. “He was kind, quiet, gentle, sincere and devout,” said Mr. Cartiff.

Image David Rosenthal, left, and Cecil Rosenthal.

Since his wife died two years ago, Mr. Wax had lived simply, with few possessions, in a Squirrel Hill apartment building where most of the residents were elderly and Jewish. “It was a community within a community,” said Mr. Cartiff.

He is survived by a daughter, Jodi Kart, 52, and a grandson.

Mr. Wax was a lifelong fan of the Pirates, a baseball team that for much of the past 25 years has been mired in mediocrity. They have not won a World Series since 1979, one of baseball’s longest droughts. But Mr. Wax was patient, even when the team’s owners over the years have drawn the ire of fans for not spending enough to keep the team competitive.

“The Pirates are always criticized for not spending money,” said Mr. Cartiff. “But he would say, ‘Oh, they don’t need to spend more millions.’ He was happy to just watch them. He didn’t care if they won or not.”

Suzan Hauptman, among those at a vigil for the victims on Sunday, recalled one of them, Dr. Rabinowitz, who was her father’s doctor when he was stricken with a serious illness.

“He helped save my father’s life and really helped me and my mother and brother get through a difficult time for us,” Ms. Hauptman said. “He was an amazing human.”

Dr. Rabinowitz was also the physician for Marie Jo Marks and her mother for about 30 years. Ms. Marks is 74; her mother, Helen Nothwang, is 102, and until recently, she lived alone in a house about two blocks from the doctor’s office.

When Ms. Marks would call with information about her mother, Dr. Rabinowitz would pledge to “walk up and see her,” whenever his day at the office was over.

“He would take her blood pressure — but he’d basically just sit up there and talk with her,” Ms. Marks said. “And that is something I will never ever forget.”

In an interview, Jerry Schmitt, another longtime patient of Dr. Rabinowitz, recalled a conversation with the doctor earlier this year. He had asked Dr. Rabinowitz, who was 66, whether he had plans to retire.

“He said, ‘Oh, I don’t think I’ll ever retire,’” Mr. Schmitt recalled. “And I pointed right at him and I said, ‘Don’t you ever retire.’ I just could not imagine going through the rest of my life without him.”

“And now,” he added, “here we are.”