This came too late for the concentration camp prisoners within the area who were now within Dönitz's nominal authority, while under the actual control of the SS. These had numbered around 10,000 when Dönitz assumed the presidency; mainly former inmates of the Neuengamme camp outside Hamburg, which had been shut down in preparation for the surrender of the city to the British. Between 16 and 28 April, the prisoners had been moved eastwards and concealed by the SS in a flotilla of unseaworthy ships anchored in the Bay of Lübeck, where they then remained without food or medical attention. At the time, this action had been opposed by Rear Admiral Konrad Englehardt on Dönitz's staff, but when the Flensburg government came into being, Dönitz made no attempt to free the prisoners, and his government avoided any subsequent acknowledgement that they had known they were there. On 3 May 1945, the prison flotilla was sunk by the Royal Air Force in the mistaken belief that the ships were being prepared to evacuate leading SS personnel. Over 7,000 prisoners drowned, mainly on the former liner "Cap Arcona".