Teen who killed baby son was "too damaged" to help.

“We weren’t able to positively impact on this young man’s life. He was too damaged.”

A 15-year-old ward of the state killed his baby son, and authorities say there’s nothing they could have done to prevent it.

The young father bashed his premature four-week-old son’s head against a door or wall in the hospital while the mother was out of the room.

The baby died from his injuries days later.

A West Australian parliamentary committee heard the teenage father had substance abuse problems and several criminal convictions including two involving violence, Perth Now reports.

Despite that, the father was allowed unrestricted access to his son.

The Director-General of the West Australian Department for Child Protection and Family Support, Emma White, told the hearing that the teen had no history of harming children.

“We had nothing to suggest those vulnerabilities would result in the tragic situation,” she said.

In the weeks before the baby’s birth, the department had trouble keeping up with the teen, who had been in state care since he was 12, because he had moved to Bunbury from Perth with the baby’s mother.

“We were running to catch up with this young man,” Ms White said.

She told the committee that the teen had completed drug and alcohol treatment, but had not started an anger management program before the incident occurred.

“Despite the effort of staff and other agencies… we didn’t make a difference,” Perth Now reports her saying.

“We weren’t able to positively impact on this young man’s life. He was too damaged.”

At the time of the bashing death, WA Minister for Child Protection Helen Morton said the teen had been involved in the day-to-day care of his son.

“From the day the baby was born, he was a regular visitor. He was involved in the feeding and the baby’s management,” Ms Morton said.

“Via the hospital staff, the Department of Child Protection and the family, it was agreed that he would visit during visiting hours. That was unsupervised.”

The teen, now 16, is currently serving a 10-year sentence for the manslaughter of his son, after pleading guilty earlier this year.

Outside court, following the sentencing hearing, his mother blamed both the government and the hospital  for the situation, saying he was not properly cared for.

“DCP took my son off me at 12 years of age, and there was no neglect,” she said.

“Since they took him, he had a criminal record and look where my son is now.

“And there was no duty of care with Bunbury hospital. He was supposed to be supervised in a locked ward, how did this happen?

“DCP did not do their job… and [neither] did Bunbury hospital.”