Senior South Australian health officials have apologised and launched a major investigation after a power failure at the new Royal Adelaide Hospital disrupted two operations.
The power outage, which lasted between 10 and 15 minutes on Wednesday morning, came when two of the hospital's six back-up generators were being tested.
A software glitch was initially blamed, but late on Thursday Health Minister Peter Malinauskas said it appeared the generators also ran out to fuel.
SA Health chief Vicki Kaminski said two operations were underway at the time and those patients did not suffer any adverse outcomes.
But she said a number of other people were waiting to use the surgery suites and would have been nervous when the lights went out.
"We're deeply sorry for it. It's not what we would hope to do," Ms Kaminski said.
The generator and engineering services at the hospital are provided by a private company and Mr Malinauskas said an investigation would seek to uncover why low fuel alarms on the generators were either ignored or did not go off and would also look into the software issue.
He said information received so far indicated the generators ran out of fuel two hours and 52 minutes into the four-hour test.
"We want to get to the bottom of exactly what happened," he said.
"To determine exactly what went wrong when and who is responsible for it and to make sure people are held accountable."
Earlier on Thursday, Australian Medical Association SA President William Tam, who was mid-surgery when the power failure occurred, said the incident was "unacceptable".
"Whether it is for 10 minutes, 20 or more, in medicine, we know that often every minute counts," Professor Tam said.
"This glitch provides a warning about what can go wrong. We need to know that it won't happen again."
Fortunately, no patients were adversely impacted, Professor Tam said.
The state opposition questioned why testing was allowed to go ahead during the middle of the day.
"There is just no way testing should be done when patients are in the operating theatre, putting their lives at risk," Opposition Leader Steven Marshall said.
The $2.4 billion hospital was opened in September.
