The biggest World War Two bomb ever found in Poland exploded under water on Tuesday as navy divers tried to defuse it. More than 750 people had been evacuated from the area near the Piast Canal outside the town of Swinoujscie where the Tallboy bomb used by Britain's Royal Air Force (RAF) was found. It weighed nearly 5,400 kg, including 2,400 kg of explosive. The Piast Canal connects the Baltic Sea with the Oder River on Poland's border with Germany. The bomb was dropped by the RAF in 1945 in an attack on the German cruiser Lutzow.