Victorian triple zero call-takers were forced to use pen and paper to dispatch emergency services for almost two hours after a system crash.
Triple Zero Victoria's computer aided dispatch system was hit by an unplanned outage about 5.30pm on Wednesday.
The crash stopped the automatic dispatch of the nearest available police, fire and ambulances crews.
Backup measures were enacted before the automatic system was operating again at 7.15pm.
"Our staff are highly trained in Victoria's CAD backup procedures, which are consistent with all other Australian jurisdictions," a Triple Zero Victoria spokeswoman said.
Premier Jacinta Allan said the cause and potential impacts of the outage were under investigation.
"When I have that further advice, or the government has that further advice, we will provide that information," Ms Allan said.
Ambulance union boss Danny Hill said call-takers manually dispatched paramedics using pen and paper when the system failed.
He said the staff were getting better at managing the crashes because they were so frequent.
"They've really got to play a high-speed chess game but the chess board is half the size of Melbourne," Mr Hill told ABC Radio Melbourne.
"(They're) trying to get the nearest crew to the nearest case."
Opposition emergency services spokesman Richard Riordan said lives had once again been placed at risk and the blame was at the feet of the Labor state government.
"Labor has managed to give Triple Zero Victoria a new logo but hasn't made a start on delivering a modern and reliable dispatch system to get emergency services to vulnerable Victorians sooner," he said.
Triple Zero Victoria, formerly known as the Emergency Services Telecommunication Authority, came under fire during the COVID-19 pandemic after 33 Victorians died as triple zero call answering times blew out.
A 2022 review by former police chief commissioner Graham Ashton found the agency was systemically underperforming, leading to dire outcomes.
Mr Ashton recommended the computer aided dispatch system be overhauled, declaring it would not meet the future needs of staff, emergency service agencies and the community.
Department of Justice and Community Safety secretary Kate Houghton told a Victorian budget estimates hearing on Thursday that it expected to sign a vendor to upgrade the system before the end of 2024.
