On April 16

The ferry MV Sewol (pictured) capsized and sank off Donggeochado, South Korea, killing 306 people, mainly students from Danwon High School.

In one of the deadliest shooting incidents in United States history, a gunman killed 32 people and wounded over 20 more before committing suicide at the Virginia Polytechnic Institute and State University in Blacksburg, Virginia (memorial pictured).

India and Bangladesh began a six-day conflict over their disputed border, which ended in a stalemate.

In response to an open letter written by white clergymen, Martin Luther King Jr. wrote the Letter from Birmingham Jail in defence of the strategy of nonviolent resistance against racism.

The Organisation for European Economic Co-operation, headquartered in Paris, was founded.

Second World War: British and Canadian forces concluded the Liberation of Arnhem in the Netherlands from German occupation.

Polish–Soviet War: The Polish army launched the Vilna offensive to capture Vilnius (now in Lithuania) from the Red Army.

World War I: Several French army corps began a massive assault against the German-occupied Chemin des Dames ridge, south of Laon, France.

American pilot Harriet Quimby (pictured) became the first woman to fly across the English Channel.

Slavery in Washington, D.C., ended when the District of Columbia Compensated Emancipation Act became law.

French Revolutionary Wars: Severely outnumbered French forces repulsed an Ottoman attack at the Battle of Mount Tabor in present-day Israel.

A revolt of citizens in Toledo, Castile, opposed to the rule of the foreign-born Charles I began when the royal government attempted to unseat radical city councilors.