Both QLD and SA islanded from the rest of the NEM on Saturday 25th August 2018

Both the QNI and the Heywood interconnectors tripped around the same time on Saturday 25th August 2018 (not apparent at this time which one was first, and why), leading to both QLD and SA regions being separately islanded from the rest of the mainland NEM. This also contributed to over 1,000MW of load shedding in NSW and VIC, and presumably some frequency excursions in QLD and SA.