The Bureau of Meteorology says wind gusts up to 260km/h from a 鈥渟upercell鈥 thunderstorm and multiple tornadoes were recorded on September 28, destroying transmission towers and causing the state-wide blackout in South Australia.
The report from the BoM 鈥 which mapped the passage of storms and seven tornadoes over critical network infrastructure 鈥 makes it clear that a freak weather event was responsible for the grid blackout.