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.

In that moment, the pregnant mother 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 all but 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, he’d been having coffee nearby when the shooting began. His father told BBC Arabic Ahmed “saw the victims, the blood, women and children lying on the street, and then acted”.

Footage of the moment he sprung out from behind a car and wrestled a gun off one of the attackers immediately went viral. He was shot multiple times, and may lose his arm.

Another man, Reuven Morrison, was also seen on the video hurling objects at the same attacker in the moments after Ahmed disarmed him.

Sheina Gutnik easily recognised her dad in the footage.

“He is not one to lie down. He is one to run towards danger,” Ms Gutnick told BBC partner CBS News.

He had jumped up the second the shooting started, she said, and was throwing bricks at one of the gunmen before he was fatally shot.

“He went down fighting, protecting the people he loved most.”

The first two victims of the assault, Boris and Sofia Gurman, were also captured on dashcam footage grappling with one of the men for his weapon. When they succeeded, he got another gun from the car he’d just climbed out of and killed them.

“While nothing can lessen the pain of losing Boris and Sofia, we feel an overwhelming sense of pride in their bravery and selflessness,” the couple’s family said in a statement.

“This encapsulates who Boris and Sofia were – people who instinctively and selflessly tried to help others.”

The list goes on.

Chaya, only 14 years old, was shot in the leg while shielding two young children from gunfire.

Jack Hibbert – a beat cop just four months into the job – was hit in both the head and the shoulder but continued to help festival attendees until he physically couldn’t, his family said. The 22-year-old will survive, but with life-changing injuries.

Lifeguard Jackson Doolan was photographed sprinting over from a neighbouring beach during the attack, armed with critical medical supplies. He didn’t even pause to put on shoes.

Others at Bondi rushed from the beach into the fire, their red-and-yellow lifesaving boards working overtime as stretchers. One lifeguard even dived back into the surf to save swimmers who’d been sent into a panic by the shooting.

Student Levi Xu, 31, told the BBC he felt he could not shout for help, as he didn’t want to draw attention to himself or risk any potential saviours being targeted.

But lifeguard Rory Davey saw him and his friend struggling, and dragged them back to shore.

“We stood up and wanted to thank him, but he had already gone back into the sea to rescue other people,” says Mr Xu.

Thousands of Australians flocked to donate blood, dwarfing the previous record.

Authorities say many off-duty first responders travelled to Bondi on Sunday – from as far as two hours away – simply because they knew there was a need.

Healthcare workers rushed to hospitals when they heard of the attack, whether or not they were on shift, confronting unspeakable trauma to save lives.

“Normally on a Sunday night, there is staff available to run one operating theatre [at St Vincent’s Hospital]. There were eight operating at once,” Prime Minister Anthony Albanese said.

State premier Chris Minns, too, has been quick to praise the heroics of ordinary, everyday Australians.

“This is a terrible, wanton act of destructive violence. But there are still amazing people that we have in Australia, and they showed their true colours last night,” he said, the day after the attack.

Wayne says he shudders to think what would have happened without people like Jessica and Ahmed.

When he speaks to the BBC, he’s just attended a funeral for the gunmen’s youngest victim, 10-year-old Matilda.

“I was sitting at this funeral and I was just thinking, tears pouring out of my eyes… I could have been in the front… It could have been my little girl.”

“There could have been so much more devastation without the bravery of [these] people… someone who could run just comes in. Someone who could worry about their own child looks after another child.

“That’s what the world needs more of.”

Additional reporting by Fan Wang.