On September 28, the 2016 South Australian blackout affected the entire state of South Australia (1.7 million people), owing to two tornados that destroyed three critical elements of infrastructure, and the power system protected itself by shutting down. While some politicians and commentators have tried to link this power failure with the state's high mix of renewable energy sources (particularly wind energy), some experts have indicated that the blackout had nothing to do with this. A number of technical reports in the previous 18 months expressed concern that the reliability and security of the power supply in South Australia had decreased following the introduction of substantial wind power, and the consequent withdrawal of major conventional power stations.