The big question: How could this happen?

Premier Jay Weatherill has already given a reply on this, saying there's no issue with a lack of baseload power (40 per cent of South Australia's power comes from renewables). He says the damage to the network caused a frequency surge in the power network and automatic fail safes triggered to cut generators and the interconnector. He says this needed to happen to protect the national power network.

Federal Energy Minister Josh Frydenberg was just on 7.30 and confirmed that wild weather blew over transmission towers in the state's north and lightning struck a power station, combining to cause this situation.