What happened to Kayla Kendrigan in the six torturous hours before she was thrown off a bridge.

Before being thrown off a Sydney bridge last weekend, Kayla Kendrigan endured six hours of what police have described as torture.

The 19-year-old survived the ordeal, which ended with her being thrown off Windsor Bridge into the Hawkesbury River, and her four attackers facing attempted murder charges.

Police allege Kendrigan, who has learning difficulties and was born without a right arm, was kidnapped by former friends from Ambarvale and tortured.

News.com.au reported court documents claim Kendrigan was forced into the boot of a car and driven about 50kms north to a house in Whalan.

It was at this house that Kendrigan endured six torturous hours.

She was blindfolded and tied to a chair with an iPhone charging cable. Once restrained, she was punched, beaten with a wooden bat and stabbed multiple times.

According to police, she sustained “significant injuries” including two stab wounds to her lower legs, deep bruising to her head and face, soreness to her upper body and lower back, burn marks to her hand and severe emotional trauma.

Speaking to news.com.au, Kendrigan’s sister Imogen Gibson said the teen was “still in a lot of pain” following her traumatic ordeal.

The harrowing night ended with Kendrigan once again bundled into a car, still blindfolded and bound. She was driven to Windsor, more than 60km away from her original location

Here, she was allegedly pushed off Windsor Bridge bridge and into the Hawkesbury River about 5am on Sunday. She was still tied up.

Gibson said she couldn’t believe anyone would do this to her sister.

“I never will be able to understand why someone would do this to her. She was always sweet and gentle. She never got into fights or hit anyone.

“It pains my heart so much because my sister was born with one arm, so she has never been able to swim or fight, but she fought through that terrible night like a fighter.”

Police said Kendrigan struggled to swim or float, but was able to make her way to the side of the river bank.

She then raised the attention of a nearby residence.

Kendrigan was taken to Nepean Hospital and treated for serious injuries, but she has now been discharged.

Four people – a 19-year-old woman, 22-year-old man, 17-year-old girl and 16-year-old body – were this week charged with attempted murder, aggravated kidnapping and other offences.

Court documents allege Kendrigan was visiting a friend in Ambarvale on Saturday and asked her housemate, the 19-year-old charged, to pick her up and bring her home to Whalan.

News.com.au reported sources said the pair had known each other for about two months.

The woman, along with three other people, came to collect Kendrigan from the house.

Police will allege the group planned during the drive to assault Kendrigan on arrival over an earlier verbal argument between the victim and the co-accused 17-year-old girl.

Police documents read the group had “no regard” to whether their actions brought about the death of the victim.

Following the events, Kendrigan’s father Ian wrote on Facebook that his daughter was lucky to be alive.

“I would like to say from the bottom of my heart a huge thank you to police and detectives you have done a fantastic job,” he wrote.

The four accused remain in custody.

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