The spring and summer of 2010/11 saw an exceptionally strong La Niña push warm waters from Indonesia down the Western Australian coastline, resulting in a host of extraordinary biological oddities including significant bleaching of Western Australian corals. Here, we report a 79–92 % decline in coral cover for a location in the Ningaloo Marine Park where sustained high water temperatures over an 8-month period left just 1–6 % of corals alive. The severity of bleaching provided an opportunity to investigate the resilience of different taxo-nomic groups and colony size classes to an acute but protracted episode of thermal stress. While the sub-domi-nant community of massive growth forms fared reasonably well, the dominant Acropora and Montipora assemblages all died, with the exception of the\10 cm size class, which seemed immune to bleaching.