The MS Estonia was a passenger ferry built in 1979 in Germany owned by Swedish-Estonian ship company Nordström & Thulin which sank on 28 September 1994 on route from Tallinn, Estonia to Stockholm, Sweden carrying 989 people, including passengers and crew.
She was expected to arrive in Stockholm at about 09:30 AM, but a few minutes past 01:00, in the outskirts of Turku archipelago the bow visor was torn off the ship by the pressure of the waves and water accumulated in the car deck. Soon the vessel lurched some 30-40 degrees to the right.
Mayday was communicated by the ship crew and rescue helicopters arrived on the site a couple of hours later.
The Viking Line passenger ferry MS Mariella that was hurrying to the place of the accident had the last radar observation of Estonia at 02:04.
A total of 94 passengers and 43 crew members were rescued from the life boats.
In the aftermath of the disaster, many relatives of the deceased demanded that their loved ones should be raised and given a land burial. Demands were also made that the entire ship should be raised so that the "real reason" for the disaster could be discovered by minute inspection.
In fear of the major financial burden such an operation could incur, the Swedish government overhastily suggested burying the whole ship in situ with a shell of concrete. This led many to interpret that there was something they wanted to hide. Soon a minor industry of conspiracy theory interpretations of the events culminated with an American adventurer and his crew diving to the wreck and filming its hull with inconclusive results.
The location of the hull is: 59° 23' N 21° 42' E, about 22 nautical miles on bearing 157° from Utö island, Finland.