When bullets began flying at Sydney's Bondi Beach on Sunday, strangers Wayne and Jessica found themselves in the same nightmare scenario. They couldn't find their three-year-olds.

In the chaos, separately, they desperately scanned the green. People who'd gathered to celebrate the first day of Hanukkah screamed and ducked. Others ran. Some didn't make it far.

The 10-odd minutes that followed were the longest of their lives.

Wayne's body was acting as a human shield for his eldest daughter, but his mind was elsewhere: with his missing daughter Gigi.

We had to wait all that time for the gunshots to stop. It felt like eternity, he tells the BBC.

Unbeknown to him, Jessica's gaze had caught on a little girl in a rainbow skirt, confused, scared, and alone - calling out for her mummy and daddy.

She couldn't protect her own child, so she'd protect this one, she decided. She smothered Gigi's body with her own, and uttered I've got you, over and over again. They could feel the moment a woman about a metre away was shot and killed.

By the time the air finally fell silent, Wayne had become convinced Gigi was dead.

I was looking amongst the blood and the bodies, he says, growing emotional.

What I saw - no human should ever see that.

Eventually, he caught a glimpse of a familiar colourful skirt and found his daughter, stained in red - but okay, still shrouded under Jessica. Her son too would soon be found, unharmed.

She said she's just a mother and she acted with mother instincts, Wayne says.

[But] she's a superhero. We'll be indebted to her for the rest of our lives.

It is one of the incredible accounts of selflessness and courage that have emerged from one of Australia's darkest days.

Declared a terror attack by police, it is the deadliest in Australian history. Dozens were injured and 15 people - including a 10-year-old girl - were killed by the two gunmen, who police say were inspired by the jihadist group Islamic State (IS).

More people undoubtedly would have been harmed if it weren't for Ahmed al Ahmed, a Syrian-Australian shop owner who saw the chaos unfurling nearby. Footage of him wrestling a gun away from one of the attackers quickly went viral, despite him being shot multiple times in the process.

Others at Bondi rushed from the beach into the fire, their red-and-yellow lifesaving boards working overtime as stretchers. Students and off-duty responders came together, showing the remarkable spirit of solidarity and resilience in the wake of devastation.

Prime Minister Anthony Albanese praised the heroics of ordinary Australians, underlining the need for more bravery and compassion in the world. There could have been so much more devastation without the bravery of these people... he said poignantly.