Passengers onboard a Qantas A380 flight from Los Angeles to Melbourne were woken by a 'loud bang' and 'shudder' just a few hours into the 15-hour flight.
A report released on Thursday by the Australian Transport Safety Bureau said one of the Airbus A380's four engines was shut down after warning signs began to appear in the cockpit.
Many of the 484 people onboard heard the bang.
The report said immediately after the cockpit warnings began, the first officer received a call from a cabin crewmember who said they'd heard a bang and that the aircraft was vibrating.
He then received another more alarming call from economy class, where a passenger said they'd seen flames and sparks coming from one of the A380's engines.
As the captain and his crew started running through their emergency checklists, the flight made its way back towards Los Angeles.
It spent some time jettisoning fuel before landing safely at Los Angeles Airport just over two hours later.
The investigation found internal corrosion of the low-pressure turbine blades in the affected engine. This resulted in fatigue failure.
Rolls-Royce, the manufacturer of the aircraft's four engines conducted their own investigation and they too found corrosion on the turbine.
The report praised the crew onboard for their fast communication and also said the incident highlighted the importance of regular maintenance.