The youngest victim of the London Bridge attack was fatally stabbed in the neck after she fell over in her high heels, an inquest heard.
Australian Sara Zelenak, 21, appeared to lose her balance just at the terrorists crashed their hire van into railings on the bridge and got out armed with 12 inch ceramic knives.
Briton James McMullan, 32, rushed to help her up but they were both set upon, the Old Bailey was told.
Ms Zelenak suffered deep gashes to her neck and Mr McMullan was stabbed once in the chest.
Police officers found Ms Zelenak mortally injured still clutching her mobile phone and immediately started CPR.
However, the court heard there were only three paramedics around as the scene was made safe, and one of them decided she could not be saved.
Erick Siguenza filmed terrified people screaming and running away as Ms Zelenak and Mr McMullan were attacked.
He told the court: "As soon as the van crashed they stepped out and the driver stabbed the woman that had jumped out to get out of the way of the van crashing. That's when they started stabbing her. I believe there was a gentleman trying to help her get up and he was stabbed as well.
"As I was recording there was a lot of screaming and just people realising what was going on and just shouting in general."
Gareth Patterson QC, representing the victims' families, said: "We know Sara Zelenak was found within minutes at the top of the steps and we know the young white woman with long hair had stab injuries.
"We also know she was wearing high heels and on the ground it was quite wet that night.
"From what you saw of this man helping her, did you get the impression she lost her balance?"
The witness said: "Yes. She was completely on the ground. He just grabbed her left arm and gently tried to pick her up but by then the attackers were in close proximity and that's when they started attacking.
"There was no time for him to be able to help her up because the driver and the other terrorists were already running towards them."
The inquest heard how Ms Zelenak had been out for a drink with her friend Priscila Goncalves on the evening of June 3 2017.
CCTV footage showed Ms Zelenak in blue jeans, white shirt, leather jacket and black lace-up high heel shoes.
Giving evidence, Ms Goncalves told how they were heading to a bar by London Bridge when they heard a "crash".
She told the court: "When we were going down the stairs and then I heard something and then we went up the stairs to see what happened and people started saying 'run' and that's what we did.
"It sounded like a crash to me. It sounded like it was something big which is why we went back to take a look.
"I thought I had seen the van but now I don't think I had actually. I was just very confused."
She said: "I had no idea what was going on. We were together. People said run. I started to run. I thought she was with me and then I looked, she was not. Everybody was running.
Ms Golcalves tried to contact her friend on Facebook after she took refuge in a hotel but she was unable to get a response.
Mr Patterson QC, suggested that Ms Zelenak's high heels coupled with wet weather might have caused her to suffer an ankle injury.
He said: "Maybe those two factors contributed to make her less stable than she might otherwise have been when this sudden attack came on her."
Detective Constable Alastair Hutchison said: "Yes, that's a possibility."
Ms Zelenak and Mr McMullan were among eight people killed when Khuram Butt, 27, Rachid Redouane, 30, and Youssef Zaghba, 22, launched their van and knife rampage on London Bridge and in Borough Market.
Xavier Thomas, 45, Christine Archibald, 30, Alexandre Pigeard, 26, Kirsty Boden, 28, Sebastien Belanger, 36, and Ignacio Echeverria, 39, also died in the atrocity before their attackers were shot dead by armed police.