The 21-year-old and fellow Australian Kirsty Boden were among eight people killed in the violence on the night of June 3, 2017.

Khuram Butt, Rachid Redouane and Youssef Zaghba used a van to run down dozens of people on the bridge before stabbing dozens more with ceramic kitchen knives in nearby Borough Market.

An inquest at London's Old Bailey on Monday heard Ms Zelenak and her friend Priscilla Goncalves had been walking down a staircase when they heard the van crash.

They turned back to investigate but Ms Goncalves heard people screaming "run" and fled down the steps.

"Then we start running and then I look again, she's (Ms Zelenak) not next to me anymore," Ms Goncalves told the inquest.

Across the street witness Erick Siguenza saw a young blonde woman, believed to be the Australian, slip and fall just metres from where the van crashed.

He agreed that the woman likely lost her footing because she was wearing high heels on the wet pavement.

Mr Siguenza then saw a man, who may have been Briton James McMullan, try to help her up, but the three attackers were already out of the van and had knives.

"There was no time for him to be able to help her out because the driver and the other terrorists were already running towards them, so there was no chance for them," he told the inquest.

Minutes later Police Constables Clint Wallis and Richard Norton found Ms Zelenak lying on her back in a dimly lit corner at the top of the stairs.

"I could see that there was copious amounts of blood on the floor. I could see that she had multiple stab wounds to the left side of her neck," Const Norton said.

Ms Zelenak's eyes were open but she had no pulse and she was not breathing, so the officers started CPR.

Const Wallis noticed the Australian was clutching her phone, which was flashing as her friend Ms Goncalves repeatedly tried to contact her.

The officers realised they were potentially in harm's way as well, being unarmed and hearing bursts of gunfire nearby, but they carried on.

"So whilst we were attending to Sara we were very conscious that our backs were exposed to the steps that the attackers had previously run down," Const Norton told the inquest.

"We asked members of the public to keep a look out for us and if they should see anybody that were armed, then to alert us."

The officers continued CPR for about 10 minutes.

"She showed no signs of life and we had a discussion whether we should continue or whether we could help any other people. We both agreed that we should stop," Const Wallis said.

At that point paramedic Garry Evans arrived and declared the Australian dead.

"She looked ... she wasn't breathing and she looked lifeless," Mr Evans told the inquest.

Both Const Wallis and Const Norton then went down into the Boro Bistro to try to save 36-year-old Frenchman Sebastian Belanger and 32-year-old Mr McMullan, who both died.

Canadian Christine Archibald, 30, Frenchmen Xavier Thomas, 45, and Alexandre Pigeard, 26, and 39-year-old Spaniard Ignacio Echeverria also died in the attack.

Mr Thomas and Ms Archibald were hit by the van, with the others were stabbed to death.

The coroner said another 48 people were seriously wounded, while all three attackers were shot dead by police at the scene.

Australian Associated Press