1911 - The Austrian-Czech composer Gustav Mahler passed away after completing nine symphonies and many songs, notably "Das Lied von der Erde" (The Song of the Earth).
1944 - A Polish-led Allied force expelled German troops from Monte Cassino in Italy after four months of siege.
1974 - India successfully tested its first nuclear device in the Rajasthan desert.
1977 - The United States, the Soviet Union, and 29 other countries signed a United Nations treaty prohibiting the artificial use of weather as a weapon of war, pledging not to attack each other with man-made storms, earthquakes, or tidal waves.
1980 - Mount St. Helens volcano erupted in Washington State, creating an ash cloud 2,500 miles (4,000 km) long and 1,000 miles (1,600 km) wide.
1993 - The Danish voted in a referendum to ratify the Maastricht Treaty, a year after rejecting it in a previous vote.
2003 - The world's first glass-nosed dolphin was born through artificial insemination using frozen sperm.
2005 - American actor Frank Gorshin, known for his role in the 1960s television series "Batman," passed away at the age of 72.
2006 - The Nepali parliament approved a plan to limit the king's powers, including his control over the military, marking a historic step for a country that has traditionally viewed the king as a god.
2009 - Sri Lanka announced its complete victory in one of the world's most intractable wars, following the death of leader Velupillai Prabhakaran, and the control of the entire country for the first time since 1983.
2015 - Dozens were killed in a landslide in the northwestern mountains of Colombia.
