It was a perfect mid-autumn day with blue skies and temperatures approaching nearly 80 degrees Fahrenheit, the kind of weather that has made Bondi on Australia’s eastern coast one of the most sought after addresses in the world.
But by the end of the day, any sense of normalcy had been shattered. At a shopping mall a mile from the beach in the Sydney suburbs, a knife-wielding attacker stabbed nearly 20 people, including a 9-month-old girl. Six of the victims, including the girl’s mother, have died, and about a dozen others were being treated at hospitals. The attacker — whose motives remain unclear — was shot and killed by a police officer.
It was one of the deadliest mass killings in Australia in recent decades and has left many in shock, questioning how a tragedy of this magnitude could occur in a country known for its relative safety.
The police on Sunday were combing through a crime scene spanning several floors of the sprawling Westfield Bondi Junction mall. They were also interviewing hundreds of witnesses to Saturday’s attack, trying to piece together the chronology of a rampage that punctured a sense of security in this wealthy suburb of Australia’s largest city.
Portraits of the victims, all but one of whom were women, began to emerge. They included a first-time mother, a Pakistani security guard who had fled persecution, and a young fashion employee, according to statements from those who knew them.
Police officials identified the attacker as 40-year-old Joel Cauchi, who had arrived in the Sydney area a month ago from Queensland, in the country’s northeast.
Why the man, who the police said had a history of mental illness, began terrorizing shoppers on Saturday afternoon, moving through the upper floors of the mall and stabbing people with a long knife, remained unclear.
“There is still to this point nothing we have received that would suggest this was driven by any particular motivation, ideology or otherwise,” Anthony Cooke, the assistant police commissioner for New South Wales, the state that includes Sydney, said in a briefing on Sunday morning.
Mr. Cauchi had had a number of interactions with the police in Queensland because of his mental problems, the authorities said, but he had never been arrested.
By Sunday evening, the police had identified only one victim, Jade Young, 47. But the family of another victim, Ashlee Good, confirmed in a statement that she and her young baby daughter were among those stabbed. The baby underwent hours of surgery on Saturday and was doing well, the family said, but Ms. Good did not survive.
“We are struggling to come to terms with what has occurred,” Ms. Good’s family said in a statement on Sunday.
The Ahmadiyya Muslim community said in a statement that 30-year-old Faraz Tahir, a security guard, had died trying to protect others during the attack. He had arrived in Australia a year ago as a refugee from his native Pakistan and had quickly become a dedicated member of the local Muslim community, the statement said.
In another social media statement, the White Fox Boutique, an online fashion retailer, said that one of its employees, Dawn Singleton, was among the victims. She was an e-commerce assistant who had graduated from college in 2019, according to her page on LinkedIn.
By midday Sunday, a makeshift memorial across the street from the mall had grown to a pile of about 100 flowers, wreaths and a balloon, and residents walking their dogs or with their morning coffee stood nearby talking about their disbelief at what had happened.
Hedy Davant, 71, who has lived a couple of blocks from the mall for three decades, said the mall was a focal point for the area, where she would go nearly every day to shop, to get dental care or sometimes just to walk around.
“It’s where the community gets together,” said Ms. Davant, who wasn’t there at the time of the stabbing. “It’s sad. It’s a really nice area, and we don’t need this.”
Kristie Spong, 54, who had just been to the mall with her daughter a few days earlier, returned Sunday to lay flowers, her makeup running down her face along with tears.
“These things don’t happen in Australia,” she said. “We just think we’re a blessed country because we have good gun control.”