A power failure at Sydney Airport’s domestic terminal caused serious delays and cancellations.
The lack of power meant airlines, including Jetstar, Tigerair Australia and Virgin Australia, were unable to check in thousands of passengers.
The power went off during the peak morning period, just before 9.30am local time.
Two hours later, the airport issued a statement saying it had identified an issue with a substation, which caused the power interruption and affected back-up power sources.
Power was finally completely restored just before 1pm.
The airport kept passengers informed via Twitter and handed out bottles of water to those stranded.
According to the local press, the chaos continued even after the power came back on.
Australian Federal Police blocked off the main entrance to the terminal to make way for several ambulances, fire crews and police.
The Australian said the outside area looked like a "refugee camp with clusters of families and friends sitting on the pavement".
Virgin Australia initially told passengers not to turn up at the airport and offered them the option of transferring to a different date or getting a full refund.
Later it said flights had restarted but warned of further delays and cancellations.
Jetstar cancelled up to 20 flights, transferring passengers to Qantas and other Jetstar flights, also offering customers the option to travel on other dates or full refunds.
A Tigerair spokeswoman said most of its morning flights were able to leave before 8.30am and were not affected by the power failure.
