World War II: The Wilhelm Gustloff, overfilled with German refugees, sinks in the Baltic Sea after being torpedoed by a Soviet submarine, killing approximately 9,500 people.

MV Wilhelm Gustloff was a German military transport ship which was sunk on 30 January 1945 by Soviet submarine S-13 in the Baltic Sea while evacuating civilians and military personnel from East Prussia and the German-occupied Baltic states, and German military personnel from Gotenhafen (Gdynia), as the Red Army advanced. By one estimate, 9,343 people died, making it the largest loss of life in a single ship sinking in history.

A refugee, according to the United Nations High Commissioner for Refugees (UNHCR), is a person "forced to flee their own country and seek safety in another country. They are unable to return to their own country because of feared persecution as a result of who they are, what they believe in or say, or because of armed conflict, violence or serious public disorder." Such a person may be called an asylum seeker until granted refugee status by a contracting state or by the UNHCR if they formally make a claim for asylum.

The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North and Central European Plain regions. It is the world's largest brackish water basin.

A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such a device was called an automotive, automobile, locomotive, or fish torpedo; colloquially, a fish. The term torpedo originally applied to a variety of devices, most of which would today be called mines. From about 1900, torpedo has been used strictly to designate a self-propelled underwater explosive device.