Historical timeline for April 4

The impeachment of President Yoon Suk Yeol of South Korea in response to his declaration of martial law is unanimously upheld by the country's Constitutional Court, ending his presidency.

Russo-Ukrainian war: The Battle of Chasiv Yar begins.

Finland becomes a member of NATO after Turkey accepts its membership request.

China holds a national day of mourning for martyrs who died in the fight against the novel coronavirus disease outbreak.

Syria conducts an air strike on Khan Shaykhun using chemical weapons, killing 89 civilians.

Seventy-four people are killed in a building collapse in Thane, India.

Georgian Airways Flight 834 crashes at N'djili Airport in Kinshasa, killing 32.

A magnitude 7.2 earthquake hits south of the Mexico-USA border, killing at least two and damaging buildings across the two countries.

France announces its return to full participation of its military forces within NATO.

The MPLA government of Angola and UNITA rebels sign a peace treaty ending the Angolan Civil War.

Space Shuttle program: Space Shuttle Columbia is launched on STS-83. However, the mission is later cut short due to a fuel cell problem.

Comet Hyakutake is imaged by the USA Asteroid Orbiter Near Earth Asteroid Rendezvous.

Three people are killed when KLM Cityhopper Flight 433 crashes at Amsterdam Airport Schiphol.

Senator John Heinz of Pennsylvania and six others are killed when a helicopter collides with their airplane over an elementary school in Merion, Pennsylvania.

Forty-one people are taken hostage inside a Good Guys! Electronics store in Sacramento, California. Three of the hostage takers and three hostages are killed.

The current flag of Hong Kong is adopted for post-colonial Hong Kong during the Third Session of the Seventh National People's Congress.

Governor Evan Mecham of Arizona is convicted in his impeachment trial and removed from office.

Garuda Indonesia Flight 032 crashes at Medan Airport, killing 23.

President Ronald Reagan calls for an international ban on chemical weapons.

Space Shuttle program: Space Shuttle Challenger makes its maiden voyage into space on STS-6.