Ena 2

On 28 June 2004, the German chemical tanker Ena 2, loaded with 960 tonnes of sulphuric acid, collided with the container ship Pusan Senator as she was carrying out her stowage operation. The chemical tanker managed to moor before sinking. The collision damaged the outer hull of the vessel, however the internal structure was not affected.
The accident caused a small amount of pollution, due to a leak of pollutant in the ventilation system. Eleven people were affected by toxic fumes of corrosive gas. Thousands of fish were killed. The pollution was quickly controlled, as the reservoirs remained intact.
After much analysis so that the vessel would not break during the operations, the tanker was refloated on the 5 July without any significant leaks.
The German authorities announced that the commanding officer had carried out operations under the influence of alcohol (blood-alcohol level of 2.1 g).