On September 28, 1994, shortly after one in the morning, the car and passenger ferry MS Estonia sank in the Baltic Sea, about 40 nautical miles south of the Finnish island of Uto, on the overnight run from Tallinn to Stockholm. There were 989 aboard. Eight hundred and fifty-two died, most of them trapped below decks, and 137 survived.
The ship had left Tallinn at about seven the previous evening in weather that was bad and got worse: wind of about 20 metres a second, gusting higher, and waves of four to six metres. She was a ro-ro ferry of about 15,500 tons built in 1979, carrying 803 passengers and 186 crew, with a car deck running most of her length and a bow visor that opened upward.
What happened on the ship is known partly from the survivors and partly from the wreck. At about 1:15 there was a loud bang, and the ship took a heavy list, first about 15 degrees and then 30 to 40. The bow visor had broken away, taking the ramp behind it with it, and water had got onto the car deck, where a ro-ro ship cannot afford to have it: an open deck full of water is free surface, it moves, and it capsizes the ship.
The alarm went out at 1:22 and the last Mayday at 1:50, . She was gone by 1:55. The emergency lasted about half an hour, which was not enough time in a storm at night for people on the lower decks, in cabins with no portholes, to find their way up. Most of the survivors were young men who had been awake and near the top.
Fifty-five of the dead were Swedes and 285 were Estonians, and 501 were unidentified or never found. The wreck lies at a depth of about 80 metres and was declared a grave site, which is why the bodies were never recovered and why diving on it is prohibited.
The official inquiry, published in 1997 by a joint Estonian, Finnish and Swedish commission, found that the visor's locking mechanism had failed under the load, that the ship had been sailing with a known defect, and that there had been no alarm on the car deck and no time. It did not find a bomb, which is what the conspiracy theories say.
The regulations changed after it. The Stockholm Agreement, and later the SOLAS rules, required water on deck detectors, higher standards for bow doors, and stricter damage stability for ro-ro ships built to older standards. A Swedish television documentary in 2020 found a previously unreported hole in the hull and the case was reopened for examination in 2021.