Erin Shi was only 18 years old when she was one of dozens of pedestrians allegedly mowed down by an out-of-control car zooming down Melbourne's Bourke Street.

Doctors said her head impact was so bad she should have died instantly, and declared she wouldn't be able to walk if she ever woke up from her induced coma.

The grim diagnosis was the best they could offer for Erin's heartbroken parents, who arrived at the hospital to find their daughter broken and battered.

The teenage girl suffered severe head and spinal injuries, along with a broken arm and shattered rib cage.

Doctors feared for her life, and the general presumption was that her death would take the death toll to seven, with the youngest victim just a three-month-old baby.

'They explained how serious her head injury was and said there was no hope for her life, none at all,' Erin's mother Jiana told the Herald Sun.

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Erin Shi (pictured) was only 18-years-old when she was plowed down during the Bourke Street rampage

Scenes of destruction flooded media channels immediately after the Bourke Street rampage, as emergency services rushed to the aid of victims (pictured)

After five days in a deep coma, doctors told her mother it was a miracle she was still alive.

But that would only be the beginning of Erin's miraculous tale of survival.

After 25 days, Erin finally woke up. At first, she didn't recognise her mother, couldn't talk and offered little emotional reaction at all.

She appeared uncharacteristically aggravated and had no memory of her past.

A few days later, mother Jiana saw something that gave her hope: a single tear streaming down her daughter's face.

As the days went on, brave Erin continued to defy the odds and slowly began speaking bits and pieces to friends and family.

She still had no memory of the crash which left her hospitalised, due to amnesia.

Nurses had imposed a strict technology ban to prevent her from finding out what had happened, fearing it could worsen her amnesia and halt her progress.

The car was allegedly driven by Dimitrious Gargasoulas, and resulted in six casualties, the youngest being only 3 months old

Emergency services (pictured) were on the scene to assist those who had been maimed in the senseless attack

As the days went on, Erin was discharged from the Royal Melbourne Hospital and taken to Epworth Hospital to begin rehabilitation.

By this stage, she was determined to find out what happened to her.

The last thing she remembered from January 20, 2017, was shopping with a friend in the city.

Shi googled her name, followed by 'Bourke Street' which led her to all the grisly information.

'It took a few months to piece it together. I used YouTube, Google and even went back to Bourke St to try to understand. But I remember nothing, nothing at all,' she told the Herald Sun.

Dimitrious Gargasoulas (pictured) allegedly drove a car into a busy Melbourne shopping precinct, killing taking six innocent lives and injuring others

Erin Shi remembered nothing of the incident on January 20, 2017, telling doctors the last thing she remembered before waking up in hospital was shopping with a friend

The ordeal stripped Erin and her family of over a year of her life.

She missed her 19th birthday, has been subject to months of rehabilitation and physiotherapy, and is still on the long road to recovery.

'My psychologist said that even 10 years on, people who have survived traumatic events still suffer problems, so that scares me, but I try to take each day as it comes.'

Dimitrious Gargasoulas (pictured) is currently facing an investigation hearing to decide whether he is mentally fit to stand trial over the Melbourne rampage

Earlier that morning he led police on a wild car chase through Melbourne with a female hostage in the passenger seat, who police said was 'not connected' to him.

The woman escaped or was let out of the car near Docklands just west of the Melbourne CBD.

Police made a decision to halt the pursuit, in fear of injuring pedestrians.

A helicopter was sent to track the car in order to find a more secure location to apprehend him.

Instead, they saw the driver plow into the busy Melbourne street, leaving six dead and 26 in hospital.

Dimitrious Gargasoulas has been charged with six counts of murder and 28 counts of attempted murder over the Bourke Street massacre in January last year.

On Friday, a judge discharged a jury after they were unable to unanimously decide whether the 28-year-old accused killer was mentally fit to stand trial.

During the attack, people ran for their lives (pictured) running into shop fronts and in haphazard directions to keep clear of the assailant

Busy Bourke Street (pictured) was rocked by the violent attack, which stripped Erin of an entire year of her life