Police officer Ashley Wildey rushed to the scene as the Bondi stabbing horror unfolded... only to learn his fiancee was among the victims

The police officer fiancé of a 25-year-old woman who was killed in the stabbing rampage at Bondi Junction rushed to the shopping centre to help his colleagues, only to discover his wife-to-be was one of the victims. 

Dawn Singleton, the daughter of multi-millionaire advertising guru John Singleton, was due to marry her high school sweetheart, NSW Police Officer Ashley Wildey, in coming months. 

Ms Singleton's life was tragically cut short, along with five other shoppers, when she was stabbed at Bondi Junction Westfield by Joel Cauchi, 40, on Saturday afternoon, while shopping for her wedding.

'She'd just gone in to buy makeup at Chanel, she was only there for 15 minutes, looking at makeup for her wedding,' a friend told the Daily Telegraph.

Mr Wildey, who was reportedly on call, rushed to the shopping centre to assist police colleagues with the unfolding situation.

'He had arrived at Westfield when officers realised his fiancée was one of the victims,' a source said.

Mr Wildey was allowed to leave the scene to be comforted by family and friends, as is procedure.

Dawn Singleton (pictured left) was shopping for her wedding. Her fiancee Ashley Wildey (pictured right) rushed to the shopping centre to help his colleagues, only to discover his wife-to-be was one of the victims

John Singleton's daughter Dawn, 25, has been named among six people murdered by knife wielding attacker Joel Cauchi at Bondi Junction Westfield on Saturday

Dawn is the oldest of three daughters to  John Singleton and his former wife Julie Martin (the couple pictured above)

READ MORE: Heroic 'bollard man' who fought off knife-wielding maniac on escalator at Westfield Bondi Junction reveals what it was like to come face-to-face with the killer 

Damien Guerot picked up a retractable barrier and confronted killer Joel Cauchi, 40, as he advanced menacingly up an escalator (pictured)

Affectionately known as Dawnie, the 25-year-old is one of Singleton's three daughters from his marriage to Julie Martin. He has eight children in total.

Last week, she bought her wedding dress and started sending out 'save the date' invitations to her loved ones and friends ahead of the special day. 

The tragic new details come as Australian fashion powerhouse White Fox Boutique paid tribute to Ms Singleton, who worked as the company's e-commerce assistant.

'Dawn was a sweet, kind-hearted person who had her whole life ahead of her,' the company wrote on Instagram.

'She was really amazing. We are all truly devastated by this loss.

'We send our condolences to her partner, the Singleton family and her friends. She will always be remembered as part of the White Fox family.' 

Ms Singleton was the second victim of the horrifying attack to be identified after it was revealed osteopath and first-time mother Ashlee Good, 38, had passed away in hospital on Saturday night.

Ms Good's nine-month-old daughter was also injured in the attack and is in a serious but stable condition after undergoing emergency surgery.

Double Bay architect and mother-of-two Jade Young was identified as a third victim of the attack on Sunday. 

Police were called to the shopping precinct at 3.20pm as Cauchi, brandishing a large hunting knife, chased after men, women and children.

Footage posted online shows terrified shoppers running outside to escape or taking shelter in shops as a siren blasted through the centre, urging shoppers to evacuate.

Inspector Amy Scott was patrolling nearby and was first on the scene. She entered the shopping centre by herself and bravely ran towards the offender, before shooting him dead when he lunged towards her with the knife.

Eleven people including Dr Good's 9-month-old child, eight other women, and two men were treated by paramedics and taken to various Sydney hospitals.

Some have since been discharged while others remain in serious conditions. 

Assistant Commissioner Cooke said there were also several other people who were injured in the attack who left Westfield and later presented to medical centres. 

Joel Cauchi from Queensland is pictured carrying a 30cm hunting knife on the escalator inside Westfield shopping centre at Bondi Junction on Saturday afternoon

Addressing reporters on Sunday, NSW Police Commissioner Karen Webb said it would take time to formally identify some of the victims of Saturday's attack as their family members reside overseas.

Cauchi has since been identified as a Queensland man who moved to Sydney in recent months.

He suffered from schizophrenia and had a transient lifestyle, with police treating the tragedy as a mental-health related incident.

The shopping centre and surrounding streets remain closed on Sunday, while police continue to scour the crime scene for forensic evidence.

Police have launched a critical incident team comprised of homicide detectives and set up Strike Force Mcauley to investigate the circumstances surrounding the incident.

The investigation will also be subject to an independent review.

As investigations continue, any witnesses, anyone with information or mobile phone vision who has not yet spoken to police, is urged to call police or Crime Stoppers on 1800 333 000.

READ MORE: New details emerge about Bondi Junction knifeman that killed six

Joel Cauchi, 40, has been identified as the mass killer in the Bondi Westfield stabbing spree on Saturday