What happened during the Able and Baker atomic tests at Bikini Atoll in 1946?

In 1946, the United States conducted Operation Crossroads at Bikini atoll to test the effects of nuclear weapons on naval vessels.1

• Test Able (July 1, 1946): A 20-kiloton atomic bomb was dropped from an aircraft and detonated 520 feet above a fleet of 80 decommissioned ships. While only five ships sank, the test demonstrated the lethal, invisible threat of radiation sickness; test animals placed on the ships succumbed to radiation, proving that while a ship might remain afloat, its crew would be killed by the blast's radiation.1
• Test Baker (July 25, 1946): A 23-kiloton device was detonated underwater at a depth of 90 feet. This explosion created a massive column of radioactive water that lifted a 26,000-ton battleship and saturated the target fleet with lethal, persistent radiation.1

The intense, lingering radioactivity following the Baker test made decontamination efforts impossible, leading to the cancellation of a planned third test, "Charlie". These tests underscored the catastrophic and indiscriminate nature of nuclear warfare, raising profound ethical concerns regarding the use of such destructive power.12