A further discussions provided unanimous agreement on the top 10 and consensus decisions on relative ranking within these. We recognise that some interventions now perceived as errors were themselves only carried out in an effort to correct the consequences of earlier decisions (i.e. there are cascading consequences): if the earlier errors can be avoided, subsequent problems may never arise. Thus, we attempt to rank the lessons identified into those that deal with the root of the problem, and those that deal with consequences further down the management line.