On September 21

Unidentified gunmen began a three-day attack on the upmarket Westgate shopping mall in Nairobi, Kenya, resulting in the deaths of 67 people with at least another 175 wounded.

American rock band Green Day released their seventh studio album, American Idiot.

Several British Muslim youths in Peterborough, England, murdered 17-year-old Ross Parker, leading to debate over whether the British media failed to cover racially motivated crimes with white victims.

A 7.7 Mw earthquake struck Jiji, Taiwan, killing 2,415 people, injuring more than 11,000 others and causing about NT$300 billion (US$10 billion) in damage across the island.

The Defense of Marriage Act was passed by the United States Congress, prohibiting federal recognition of same-sex marriage, while allowing states to adopt any marital definition of their choosing.

The Soviet Union's Zond 5 landed in the Indian Ocean, becoming the first spacecraft to safely return to Earth after travelling around the Moon.

Portugal accepted a diplomatic mission from Southern Rhodesia despite objections by Britain, which had required the colony to implement black majority rule as a condition of independence.

The first section of Interstate 80 in Iowa opened in the Des Moines metropolitan area.

Second World War: The German Army began the Massacre of the Acqui Division on the Greek island of Cephalonia, executing 5,155 Italian soldiers in the next five days.

The Great New England Hurricane made landfall on Long Island, New York, killing an estimated 682 people and injuring 1,754 others.

J. R. R. Tolkien's fantasy children's novel The Hobbit, which later served as a prelude to The Lord of the Rings, was first published.

Chandrashekhar Agashe (pictured) established the Brihan Maharashtra Sugar Syndicate Ltd., one of the oldest companies in India.

The Muroto typhoon, the strongest in Japanese history at the time, made landfall on the mainland, killing more than 3,000 and leaving around 200,000 homeless.

World War I: The Battle of Nazareth ended with the British Empire victorious over the Ottomans.

In response to a letter written by eight-year-old Virginia O'Hanlon, The New York Sun published an editorial by Francis Pharcellus Church stating, "Yes, Virginia, there is a Santa Claus".

American Revolutionary War: The Great Fire of New York (depicted) broke out during the British occupation of New York City, destroying up to 1,000 buildings.

Led by Antonio de Vea, a Spanish naval expedition departed El Callao, Peru, for the fjords and channels of Patagonia to find whether rival colonial powers were in the region.

Norman invasion of Ireland: English and Irish forces conquered Dublin, forcing Ascall mac Ragnaill, the last Norse–Gaelic king of Dublin, into exile.