Tacitus' account indicates that Agrippina the Younger had set sail on a cruise on which Nero had secreted conspirators intent on killing her. Agrippina and Acerronia, along with the steersman Crepereius Gallus, were underneath a canopy on deck which had been secretly weighted with lead. At a given signal, the canopy fell, killing the steersman, but missing Agrippina and Acerronia because of the high-backed couch they had been sitting on.Tacitus, Annals xiv. 4
