The annual Holocaust memorial ceremony on Sunday in Philadelphia was especially poignant, coming a day after the deadly shooting at a California synagogue by a gunman using an assault rifle and screaming anti-Semitic slurs.

“We mourn the recent tragic losses yesterday at Congregation Chabad,” Susanna Lachs Adler, board chair of the Jewish Federation of Greater Philadelphia, said as she stepped to the microphone at Congregation Rodeph Shalom on North Broad Street, addressing the fresh heartache of the nearly 400 in attendance.

Saturday’s attack in Poway, a community north of San Diego, left a 60-year-old woman dead. Lori Kaye was trying to shield the rabbi, who nonetheless was shot in the hand but survived, CNN reported. A 34-year-old man and a young girl were also wounded with shrapnel, according to news reports.

Authorities called the attack a hate crime, and were investigating whether the gunman, John Earnest, 19, of San Diego, had posted an anti-Semitic manifesto before the shooting on the online message board 8chan. They were also investigating his connection to arson at a mosque in a nearby town last month. He was taken into custody shortly after Saturday’s shooting.

The timing of the attack seemed calculated for maximum horror, Naomi Adler, president and CEO of the Jewish Federation in Philadelphia, said in an interview before the remembrance service began Sunday. Saturday was the last day of Passover, a holiday that celebrates Jewish liberation, and it was exactly six months after the shooting that claimed 11 lives at the Tree of Life synagogue in Pittsburgh.

“We have a lot to balance today,” she said. “We can’t let [the latest shooting] overshadow the remembrance of more than six million Jews who died in the Holocaust. But we need an extra moment for everyone to take a breath and mourn what happened in California."

The California atrocity is part of a worldwide tide of religious violence. On Easter, suicide bombers killed at least 250 people at Catholic churches and hotels in Sri Lanka, where Catholic churches suspended services out of fear of more attacks. Last month, a massacre at a mosque in New Zealand left 50 dead.

The escalating violence poses a growing dilemma for houses of worship around the world. “We are targets of hate," Adler said. "How do we ensure security without pushing people away?”

Lori Felt of Dresher echoed that sentiment as she sat in a pew in the ornate, domed synagogue. If you can’t feel safe in the place where you pray," she asked, "where can you be safe?”

The ceremony – the 55th annual gathering to remember the World War II genocide and recognize those who survived – was originally planned for the Horwitz-Wasserman Holocaust Memorial Plaza on the Benjamin Franklin Parkway, but was relocated because the forecast called for rain.

Some of the hymns, prayers, and readings felt not only inspiring, but also prescient.

The youth choir, for example, sang a Yiddish children’s hymn with a translation in the program: “We remember all our tyrants. We remember all our friends. And we pledge that in the future, our past and present blend.”

“Given what is going on in the world today," Lachs Adler said, "this day of collective public remembrance becomes all the more important. We will not succumb to fear and hatred. History has taught us we can’t be bystanders.”