The witnesses: 'There was no hesitation, he just mowed them down'

Sharn Baylis said she gave CPR to a young Asian man in his 20s who appeared to have suffered severe head injuries.

She said onlookers tried to save the man, but he died on the footpath outside Bardot on Bourke Street after being run over by the car before paramedics could help him.

"There were massive internal injuries, he was bleeding heavily but the head injury alone probably would have killed him," she said.

She ran over to help the man after watching the car travelling down Bourke Street Mall, driving in a straight line as it slammed into pedestrians.

"There was no hesitation when he got to the crowd, he just mowed them down," she said. "He was going around 60km/h but it seemed faster."

The immediate emotional reaction to the incident was disbelief, she said.

"There were a few gasps and then you started hearing yelling and a few people scream."

Children were also screaming and appeared to have injuries, she said.

The car missed Former Victorian police commissioner Christine Nixon by less than a metre. She immediately fell back on her long years of training.

"I just stood there for 15 or 20 minutes directing traffic. No one disobeyed my instructions," she said.

Ms Nixon also saw an overturned pram unattended and went to check that it was empty.

According to her account, the mother then walked up and asked: "Where's my child?"

Craig Lawrence was eating lunch near the corner of Bourke and William.

"Then I heard like bang! Bang! Bang! It sounded like three gunshots.

"I looked up, and there was a mass of people running through the forecourt, as if they thought there was a gunman chasing them. I stood up and started running."

There have been reports of a child being killed by the speeding car.

Mr Lawrence said he did not see the child get hit, but could see where the overturned stroller lay – and 50 metres further up the road, where the child was lying in the street.

"That was at least 50 metres, so the baby must have been caught up on the bonnet and just carried and then fallen off. She looked like maybe two or three. I just hope she was OK."

Kylie Clark and her 10-year-old daughter Ingrid were on the steps of H&M for an Australian Open promotion when they saw a maroon car tearing down the footpath on the opposite side of Bourke Street.

"Bodies were flying across the windscreen, and over the back, others were under the car," Ingrid said.

"He was going like a bat out of hell. Didn't care who he collected. Straight up the footpath," Kylie said.

"People were screaming. It was chaotic."

Maria Kitjapanon was walking up Bourke Street Mall from Southern Cross Station.

"I was nearly at the intersection with Swanston, and I saw the car – which was incredibly battered even by that stage – it was coming straight towards me on the footpath. it took me a couple of seconds to compute – so I stepped aside onto the road."

She saw police officers then turn the corner and ram the car.

"As I was stepping off, another police car came about and rammed into the maroon car to make it stop. There were probably 10 police surrounding that guy's car, with guns drawn, and they fired into the car.

"Then they dragged someone out via the passengers side, then all 10 of them sat on top of him."

Further down the scene, Ms Mitjapanon said she could see an overturned pram – and further on, a mother running back toward her baby.

Madison Tierney was standing directly in the path of the speeding maroon car as it raced down Swanston Street.

She and her mother had heard screams coming from higher up the street, and saw people starting to flee – before the car came racing her way.

As the car raced toward her, Madison froze – it was only the quick thinking of her mother, who grabbed her and yanked her out of the way, that kept her alive.

"The car was less than a meter away from us, really fast. My mum saw the actual person inside the car, he looked really angry. I just froze, and was pulled out of the way by my mum."

Madison's mum, Jennifer, told Fairfax: "He had dark hair. I just thought the car was out of control. the car swerved past me, onto Swanston Street, then I grabbed my daughter and ran."

Rebecca Russo was standing on Bourke Street when she heard a crash coming from the direction of the mall.

"I saw a maroon car driving up the pedestrian path on the Flinders Street side. People were running out of the way, they were going very very fast. I saw him hit a few people. Is saw bodies flying into the air."