Allies wrong
Neuengamme was evacuated in April 1945 because the Allies were advancing rapidly. Ten thousand prisoners were brought to Lubeck and imprisoned on three large ships, like floating concentration camps. The ships were located between German warships.
The British thought there were German soldiers on board. On May 3, 1945 they fired on the ships. The Cap Arcona turned into a floating conflagration. The icy water waited outside. The men who managed to escape the burning ship were shot dead by the Germans when they managed to reach land.
The Theilbek, another ship, was also fired upon by the Allies. Seven thousand prisoners died, just hours before the liberation.