A police officer was called to Westfield Bondi Junction only to learn his wife-to-be was among the victims.
Dawn Singleton, 25, was one of six people killed in Joel Cauchi's murderous rampage on Saturday afternoon.
The daughter of millionaire businessman John Singleton had been looking at make-up for her wedding, a friend told Australia's Daily Telegraph.
Her fiancé Ashley Wildey was one of numerous police officers who scrambled to the scene.
"He had arrived at Westfield when officers realised his fiancée was one of the victims," a source the Daily Telegraph.
He was allowed to leave the scene to be comforted by family and friends.
According to the Mail Online, Singleton had just last week purchased her wedding dress and was sending out save the date cards.
She worked in e-commerce at White Fox Boutique.
"Dawn was a sweet, kind-hearted person who had her whole life ahead of her,' it 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."
All six people to have lost their lives have now been named.
The others are are 38-year-old osteopath Ashlee Good, whose nine-month-old daughter was also injured, 47-year-old architect Jade Young, 30-year-old security guard Faraz Tahir, 55-year-old artist and designer Pikria Darchia and Chinese student Yixuan Cheng.
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