The medical and education hub in Murdoch was left without power yesterday after a Western Power grid failure.

The cause was initially thought to be a lightning strike that hit a Western Power substation in Cannington about 9.30am yesterday morning.

But Western Power spokeperson Paul Entwistle said the investigation conducted by the Western Power response team told a different story.

Mr Entwistle said the power outage was cause by a truck hitting a high voltage line in Cannington.

“Once we actually did the full realisation, we conducted extra investigation into an area near the substation, just to make sure no line has been hit by lightning,” Entwistle said.

“That’s when we discovered evidence that there had been a potential third party contact or a basically, a non Western Power … worker hitting the network on the HV line or high voltage line.”

High profile institutions affected by the outage included Fiona Stanley and St John of God hospitals, as well as Murdoch University and the South Metropolitan TAFE Centre.

St John of God communications manager Olivia Harvey said the hospital was affected by the outage but there were backup generators.

“We had mains power out for a little over an hour,” she said

“When that happens, the hospital’s generators are instantly activated which meant we still had critical power supply to theatres and lighting around the hospital.”

According to Ms Harvey, the main people affected were the hospital patients.

“Our main priority is the safety and comfort of patients,” she said.

“It is standard policy across all hospitals not to begin new procedures under generator power so some doctors and patients were delayed, but doctors who were currently in surgery when the outage occurred continued as normal.”

The Western Power response team managed to resolve the issue and restore full power to all southern suburbs customers at 10.30am.