The deadly attack at a Pittsburgh synagogue will "not break us", religious leaders said, after the shooting of 11 people.
Rabbi Jonathan Perlman, who helped hide people during Saturday's shooting, said: "What happened yesterday will not break us. It will not ruin us."
The rabbi, along with other congregation leaders, spoke at an interfaith memorial service on Sunday.
Suspected gunman Robert Bowers is now in the custody of US marshals.
During his first court appearance on Monday, Bowers waived his detention hearing and has requested a public defender, US media reported.
A hearing has been scheduled for 1 November.
White House Press Secretary Sarah Sanders announced during a news conference that President Donald Trump and the First Lady will travel to Pennsylvania on Tuesday.
Scott Brady, US Attorney for the Western District of Pennsylvania, says he is seeking the death penalty against the suspect. The final decision will depend on US Attorney General Jeff Sessions.
Rabbi Jeffrey Myers told journalists on Monday that the FBI is still gathering evidence inside the synagogue and that it could be at least another week before members were allowed back inside.
"There are hundreds of bullet holes in our sanctuary," he said. "I looked at this [building] and said: 'My God, this is a giant mausoleum.'"
Survivors of what is believed to be the worst anti-Semitic attack in US history recalled taking refuge and hiding in storage rooms to avoid the roaming attacker.
One congregation leader said their training in active-shooter situations had helped save lives, and that Rabbi Perlman helped lead worshippers to storage rooms where they could hide.
The 11 victims were named on Sunday and included a husband and wife, and a woman aged 97.
Another six people were injured, including four policemen.
Mayor Bill Peduto said that this was the "darkest day of Pittsburgh's history".
When the suspect was detained after a shootout, he reportedly told Swat officers he wanted "all Jews to die".
Robert Bowers, 46, now faces 29 criminal charges. He was discharged from hospital on Monday morning, local time, after being treated for multiple gunshot wounds.
Social media site Gab, which has been criticised for serving as an outlet for the far-right, has now gone offline after it was revealed the suspect had been an active member.
Bowers makes quiet first appearance in court
Analysis by Jane O'Brien, BBC News
Robert Bowers arrived shackled to a wheel chair wearing a blue shirt. His hands were untied to enable him to sign his name.
It's OK, I can scribble, he said.
The hearing lasted only a few minutes to set a date for Thursday when the prosecution will bring evidence.
He was slightly hunched and looked down when addressed by the judge who asked if he wanted to hear the complaint against him.
His lawyers declined and Bowers was remanded into the custody of the sheriff with no bail. Bowers faces federal murder and assault charges which could carry the death penalty.
He was shot and injured during an exchange of fire with police as he tried to leave the Tree of Life Synagogue where its alleged he killed 11 worshippers in America's worst hate crime against Jews.
What have the survivors said?
Three congregations were reportedly meeting at the Tree of Life synagogue in the Squirrel Hill district of Pittsburgh on Saturday morning.
Members of the New Light congregation were meeting in a basement area, Carl Solomon, 81, a congregation member who turned back from the synagogue but had spoken to survivors, told the New York Times.
Richard Gottfried, 65, and Daniel Stein, 71, were in the kitchen and both were shot dead. Congregation co-president Stephen Cohen told the paper there was "no place to hide" there.
He said Rabbi Perlman had shepherded two other people into a storage room, although one, Melvin Wax, 88, chose to later open the door and was shot dead.
Mr Cohen said "everyone froze but Rabbi Perlman". He told the Associated Press news agency that leaders had taken part in active-shooter drills "and I think that's what ultimately saved the people who were saved".
Who were the other victims?
They were named on Sunday as Joyce Fienberg, 75; Rose Mallinger, 97; Jerry Rabinowitz, 66; Cecil Rosenthal, 59, and his brother David, 54; married couple Bernice Simon, 84, and Sylvan Simon, 86; and Irving Younger, 69.
Tributes have been pouring in from those who knew the victims. Myron Snider described his friend Melvin Wax as a "sweet, sweet guy" and unfailingly generous.
Ben Schmitt, a patient of Jerry Rabinowitz, said the family medical practitioner was "kind and funny... [he] completely personified the term 'bedside manner'".
Cecil and David Rosenthal were described as "kind, good people with a strong faith and respect for everyone around".
One injured officer was released from hospital on Saturday, another was due to be released on Sunday, with the other two needing more treatment.
How was the gunman apprehended?
He was armed with three Glock handguns and an AR-15 semi-automatic rifle. He owned them legally, a law enforcement officer told the Associated Press.
Officers arrived after receiving calls about an active shooter at 09:54 local time (13:54 GMT) on Saturday and encountered the suspect as he was trying to leave.
The gunman fired at them and ran upstairs. As Swat officers searched for victims, the gunman opened fire on them and injured two. The suspect was detained after being wounded in an exchange of fire with officers.
Officials said the gunman had made statements regarding genocide as well as a desire to kill Jewish people.
What is known about the suspect?
There are few details about Robert Bowers but there is a trail of anti-Semitic comments on social media.
His neighbour, Chris Hall, told AP: "The most terrifying thing is just how normal he seemed."
Officials said there was nothing to indicate he had any accomplices.
FBI special agent Robert Jones told a press conference that Mr Bowers did not appear to be known to authorities prior to the attack.
What are the charges?
The 29 charges were announced in a statement issued by the US Attorney's Office of the Western District of Pennsylvania:
- Eleven counts of obstruction of exercise of religious beliefs resulting in death and 11 counts of use of a firearm to commit murder during and in relation to a crime of violence. These can carry the death penalty
- Four counts of obstruction of exercise of religious beliefs resulting in bodily injury to a public safety officer
- Three counts of use and discharge of a firearm during and in relation to a crime of violence
What has been President Trump's reaction?
He described the gunman as a "maniac" and suggested the US should "stiffen up our laws of the death penalty".
"These people should pay the ultimate price. This has to stop," he said.
Mr Trump has ordered US flags at government buildings to be flown at half-mast until 31 October.
He said the shooting had "little to do" with US gun laws. "If they had protection inside, maybe it could have been a different situation."
But Mayor Peduto, a Democrat, said: "I think the approach that we need to be looking at is how we take the guns, which is the common denominator of every mass shooting in America, out of the hands of those that are looking to express hatred through murder."
Ahead of Mr Trump's proposed visit, progressive activists have called on the president to change his language towards minorities and immigrants.
In an open letter, Jewish organisation Bend the Arc has said the president will not be welcome in Pittsburgh until he denounces white nationalism, ends his anti-immigrant rhetoric and commits to "compassionate" policies.
Tree of Life Rabbi Jeffrey Myers, however, told reporters that he refused to let politics enter the conversation because "hate does not know political party, religion, colour, persuasion or anything".
"We do need to have strong leadership from all of our elected leaders, not any one person - all of them, from all political parties," he added.
"When you speak language of hate as a leader, you give permission to all peoples to say it's ok to speak that language, to treat people that way. My answer is no, it's not."