A 13-year-old girl is among 1500 people reportedly sexually assaulted or harassed in mental health wards across the nation in the last six years.
Florence (not her real name) was allegedly raped at Perth Children's Hospital in January last year by another patient in the mental health ward.
"Knowing I'm not the only one genuinely shatters me," she wrote in an essay about her experience that ABC News has reported.
"We were supposed to be protected."
Earlier in the day the perpetrator, a 13-year-old boy, allegedly told Florence he was going to "do stuff" to her that night.
CCTV later captured vision of him crawling across the ward floor into Florence's room about 12.30am.
"I was just frozen, knowing he was so much larger than me," she said.
WA Health Minister Amber-Jade Sanderson said the incident was devastating and preventable, and the health system had failed Florence and her family.
"When we hand our children over to the children's hospital, we expect them to be safe," she told reporters on Tuesday.
"That is a reasonable expectation that I have as a minister and as a parent."
Nursing staff on duty that night did not do their required hourly checks between 12.30am and 3.30am and instead gathered in an office on the ward out of fear of the boy.
"It is inexplicable why security wasn't called," Ms Sanderson said.
"Security is available to staff 24/7 to support them, their supervisor also should have attended."
Staff members faced disciplinary action and counselling after the alleged rape and none of those involved continue to work in the mental health ward.
The assault was reported to WA Police who charged the boy with several offences before the matter was dealt with in the courts.
Ms Sanderson issued WA's Child and Adolescent Health Service (CAHS) board with a show cause notice asking them to provide evidence that they had taken the matter seriously and provided appropriate governance and oversight.
She said several members of the board had since been replaced, along with the majority of CAHS executives, and the ward was now as safe as it could be after changes to its operational model.
CAHS said it conducted a review after the alleged incident involving Florence and the Office of the Chief Psychiatrist and the Mental Health Advocacy Service undertook two independent investigations.
"We have taken this very seriously," chief executive Valerie Jovanovic said.
CAHS said $7.7 million had been allocated to improve the ward, including structural changes and some reconfiguration of its layout.
"I want to reassure families that patient safety remains our highest priority," Ms Jovanovic said.
Ms Sanderson committed to releasing the full recommendations from the Chief Psychiatrist's report, pending approval from the agency.
She also said the CCTV footage should be provided to Florence's family after it was revealed they had not been granted access to the vision.
WA Liberal leader Libby Mettam called for a public inquiry into the incident, saying it was inexcusable and tragic.
Florence's family is now considering legal action against the hospital over the incident.
ABC Investigations used freedom of information applications and publicly available data to establish the number of people assaulted in mental health wards.
It said the full extent of the problem remained unclear because there was no nationally consistent definition of such incidents and the data provided by state health departments was inconsistent.
Privacy laws also restrict the media from accessing hospital information.
Lifeline 13 11 14
beyondblue 1300 22 4636
Kids Helpline 1800 55 1800 (for people aged 5 to 25)
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
