Child safety services missed opportunities to protect two babies who died at their homes and failed to properly assess risk and discuss safe sleeping practices as required.
Both children, who died in 2019 while co-sleeping with their respective parents in separate incidents, were known to Tasmania's child protection system.
A coronial report published on Friday found multiple failures in the state's child safety service and made 10 recommendations for reform.
"(Their) sudden and preventable deaths ... highlight that there can be tragic consequences of placing an infant in an unsafe sleeping environment," coroner Olivia McTaggart said.
"In both cases, the infants were loved but the ability of their parents to keep them safe was limited."
In both deaths, there was a delay in the service's allocation of the cases, and inadequate recognition and assessment of risk, Ms McTaggart said.
There was also failure to discuss safe sleeping practices with the parents as required by policy.
One baby died as a result of accidental overlay by a sleeping parent.
An internal service review found the decision to discharge the infant into the parents' care was not based on adequate assessments.
The decision was incongruent with known child protection history, including the mother's alcohol and drug use, mental health issues and pattern of disengagement with services.
At the time of the infant's death, the father was sedated by methadone and other substances while the mother was affected by significant quantities of alcohol.
"The failure of child safety service to recognise the risk and take appropriate action, together with other deficits in practice, represented missed opportunities," Ms McTaggart said.
"The outcome ... may well have been different if the failures had not happened."
The other baby was the subject of an "open" child safety service notification, with the service not appreciating the mother's poor mental health, recent separation and lack of support.
"Relevant information was still being gathered in respect of the notification. However, by this time, it was too late," Ms McTaggart said.
She said the infant would not have died if placed in a bassinet on their back with no loose bedding.
Before the inquest, the service acknowledged its decision-making in both cases was inconsistent with proper policy and procedure.
Ms McTaggart noted the service had since implemented a leadership redesign and greater monitoring of sleeping practices.
She said service staff were often required to make decisions in an environment where staffing and resourcing were inadequate.
The recommendations include a call for audits to determine whether safe-sleeping messages have been delivered in line with procedure.
The state government department responsible for the service said the recommendations would be reviewed and further action taken where required.
