PITTSBURGH — David DeFelice replayed an old voicemail message this weekend, a message his friend Cecil Rosenthal left him one day last year.

It was just a few seconds long, as most of Rosenthal's messages were. Call when you get a chance, he said in his familiar, friendly, gravelly tone.

Rosenthal, 59, was fatally shot inside Tree of Life synagogue here Saturday, one of 11 victims killed during a rampage that the Anti-Defamation League said was likely the deadliest anti-Semitic attack in American history.

DeFelice, in replaying the message from Rosenthal — whom he met in 2015 through the Best Buddies program for people with intellectual and developmental disabilities — was seeking comfort and intimacy amid the unrelenting sadness of recent days.

"Just listening to his voice was nice," said DeFelice, 21.

The rampage continued to reverberate Monday, as it surely will for some time. The accused shooter, David Bowers, made his first appearance in federal court, where he faces dozens of charges and potentially the death sentence if convicted. President Trump also announced he would visit the city Tuesday to pay his respects to the victims and survivors.

All over the city Monday, residents sought to continue the grieving process and to figure out a path forward.

At the Yeshiva School in the Squirrel Hill section, staff members had consulted with mental health professionals about how to address the topic with children, said Rabbi Chezky Rosenfeld, the school's director of development.

"It's obviously a very difficult time," he said.

With 450 students from preschool through high school, Rosenfeld said, the institution had no formula for discussing the situation. Many students and staff had some degree of uncertainty Saturday, he said, because anyone attending synagogue would have been inside when all neighboring synagogues were placed on lockdown.

Rosenfeld said he did not think any students had immediate relatives among the victims. But the Jewish community in Pittsburgh is small, he said, so "everyone knew somebody." Teachers and staff Monday were seeking to acknowledge the pain of the attack but also to remain positive.

"A little bit of light can dispel a lot of darkness," Rosenfeld said.

Outside Tree of Life, mourners continued to stop at the piles of flowers, notes of remembrance, and other makeshift memorials that had sprung up on surrounding blocks. Funerals were scheduled to begin Tuesday, with services for Rosenthal and his brother David, also slain in the attack, set for noon.

David and Cecil, both of whom had developmental disabilities, were beloved in their Squirrel Hill community and at Tree of Life, their longtime place of worship.

David, 54, was in a housekeeping training program at Goodwill of Southwestern Pennsylvania. CEO Michael Smith said in a statement on Facebook: "David loved talking to people and always asked about pets, children and so many other things. He knew each person's story."

DeFelice said Cecil was similarly inquisitive, always asking questions about his parents and the next Best Buddies event. At times, DeFelice said, Cecil would call him several times a week, and they grew close despite their age gap and differences.

Rosenthal took DeFelice, who is Jewish, to Tree of Life twice. DeFelice, a student at Duquesne University, took Rosenthal to the school's dining hall, where he ate cookies to indulge his sweet tooth.

DeFelice said that the last 48 hours had been overwhelming, and that it had been difficult to comprehend that Rosenthal — with whom he had bonded because of a shared faith — was the victim of a hate crime.

DeFelice knew he would miss his friend.

"Now," he said, "it's just understanding the gravity of the situation as a whole."