Historical timeline for July 21

A Bangladesh Air Force Chengdu FT-7BGI crashes shortly after takeoff into Milestone School campus in Dhaka, Bangladesh, killing 35 people and injuring 173.

U.S. President Joe Biden announces he will no longer seek a second term and withdraws from the 2024 election, endorsing Vice President Kamala Harris as she launches her own presidential campaign.

The Barbenheimer phenomenon begins as two major motion pictures, Greta Gerwig's fantasy comedy Barbie and Christopher Nolan's epic biographical thriller Oppenheimer, are released in theaters on the same day and audiences, instead of creating a rivalry between the extremely dissimilar films, instead attend and praise both as an informal, surreal double feature.

Yuen Long attack or "721 incident" in Hong Kong. Triad members indiscriminately beat civilians returning from protests while police failed to take action.

Erden Eruç completes the first solo human-powered circumnavigation of the world.

NASA's Space Shuttle program ends with the landing of Space Shuttle Atlantis on mission STS-135 at NASA's Kennedy Space Center.

U.S. President Barack Obama signs the Dodd–Frank Wall Street Reform and Consumer Protection Act.

Ram Baran Yadav is declared the first President of Nepal.

Four attempted bomb attacks by Islamist extremists disrupt part of London's public transport system.

At the conclusion of a fireworks display on Okura Beach in Akashi, Hyōgo, Japan, 11 people are killed and more than 120 are injured when a pedestrian footbridge connecting the beach to JR Asagiri Station becomes overcrowded and people leaving the event fall down in a domino effect.

Third Taiwan Strait Crisis: The People's Liberation Army begins firing missiles into the waters north of Taiwan.

Taiwan's military police forces mainland Chinese illegal immigrants into sealed holds of a fishing boat Min Ping Yu No. 5540 for repatriation to Fujian, causing 25 people to die from suffocation.

The world's lowest temperature in an inhabited location is recorded at Vostok Station, Antarctica at −89.2 °C (−128.6 °F).

Jay Silverheels, a Mohawk actor, becomes the first Native American to have a star commemorated in the Hollywood Walk of Fame.

The start of the four-day-long Libyan–Egyptian War.

Christopher Ewart-Biggs, the British ambassador to the Republic of Ireland, is assassinated by the Provisional IRA.

In Lillehammer, Norway, Mossad agents kill a waiter whom they mistakenly thought was involved in the 1972 Munich Olympics Massacre.

The Troubles: Bloody Friday: The Provisional IRA detonate 22 bombs in central Belfast, Northern Ireland, United Kingdom in the space of 80 minutes, killing nine and injuring 130.

After 11 years of construction, the Aswan High Dam in Egypt is completed.

Apollo program: At 02:56 UTC, astronaut Neil Armstrong becomes the first person to walk on the Moon, followed 19 minutes later by Edwin "Buzz" Aldrin.