More than 300 vulnerable children fall through the cracks each year in the Illawarra due to a lack of caseworkers, Family and Community Services workers estimate.
Staff at the Coniston DOCS office joined their colleagues around NSW yesterday in lunchtime industrial action.
It is the second action taken by the child protection workers since the death of Berkeley toddler Zoran Ivanovski in August last year.
Zoran's mother Tamie Leanne Apps has been charged with his murder and is due to appear in Wollongong Local Court today.
Staff told the Mercury they were devastated and traumatised by the tragedy and claimed the two-year-old's death may have been prevented if they had more trained, permanent staff.
Zoran's case was discussed at a meeting of child protection workers in the days before his death.
He was to have been allocated a caseworker within the week, but he died before that occurred.
"To have a child die when we believe his death could have been avoided is devastating," one worker, who asked not to be identified, said.
"We're all quite traumatised. We try to do the best work we can, we do more work than we should be doing, but it's not enough, we need more caseworkers."
The child protection workers said on average there were 35 new cases a month in the Illawarra, with only enough staff to fully investigate about three to four new cases. After 28 days most of those were bumped from the system and were eventually closed, with only the most serious allocated a caseworker.
A portion of the other cases would be malicious complaints, but others, earmarked as a concern, might be held over for consideration to the following month.
Another staff member, who asked not to be identified, said most of the cases were never seen due to a lack of staff. There were also some weeks when no new cases were allocated because there was no-one to handle them.
"All emergency cases get seen," said the worker. "But there are cases we know should be allocated a caseworker which aren't.
"We watch them, we read about them when they come through and we wish that something could be done. But everyone here already has a full workload."
Just before Zoran's death the NSW government slashed eight experienced temporary positions used regularly by the Coniston service to fill in the gaps.
Since then there had been no changes to staffing levels at the Coniston office, until yesterday when two temp staff were employed on a three-month contract at the DOCS home care service.
An Ernst & Young report, leaked by the state opposition last week, showed the area was short at least 14 child protection workers, equating to more than two teams. Those teams had the potential to investigate 140 extra cases in the area.
Tracy, another worker, who did not want her last name published, said it was devastating on a personal and professional level when vulnerable families could not access the service.
"It can get pretty bad, but we're only a little piece of the jigsaw," she said. "If you don't have all the pieces you can't get the jigsaw done. We need more workers at the frontline so more cases get seen."
Public Service Association regional organiser Tony Heathwood said immediate action needed to be taken before more kids slipped through the cracks.
"The government has a responsibility for providing adequate resources to protect these vulnerable children and they're not doing that," he said.
In State Parliament yesterday, Opposition Leader John Robertson accused Minister for Family and Community Services Pru Goward of misleading Parliament and the public.
He claimed Ms Goward knew about the Ernst & Young report into critical caseworker shortages.
Ms Goward had previously denied the service was understaffed and claimed that the figures provided by the PSA were inaccurate.
Attempts by the Mercury to gain comment from the minister's office yesterday failed.