Only after World War II did the secret spill: Ōkunoshima, located in the Inland Sea of Japan between Hiroshima and Shikoku, was the top-secret site for manufacturing chemical warfare. When the factories were closed down, a number of exotic wild rabbits were seen freely roaming the island. They were assumed to have been the test subjects for the chemical weapons, which the military failed to eradicate when the factory was demolished.

A woman is helped out of the wrecked car of a train that derailed at the station of Pioltello Limito, on the outskirts of Milan, Italy, Thursday, January 25, 2018. Italian officials said that the commuter train derailed in northern Italy, killing some people, seriously injuring 10 and trapping others heading into Milan at the start of the work day. (Photo by AP Photo/Stringer)

People react as a Canadian man wearing only a pair of shorts orders a drink from a fast food outlet in Gangneung Curling Centre on day 10 of the PyeongChang 2018 Winter Olympic Games on February 19, 2018 in Gangneung, South Korea. (Photo by Carl Court/Getty Images)

Men try to get control of a bucking horse a Tradition Day rodeo exhibition during, in San Antonio de Areco, Argentina, Sunday, November 13, 2022. Tradition Day, aimed to preserve gaucho traditions, is celebrated to honor the birth of Argentine writer Jose Hernandez, author of the country's national poem, “The Gaucho Martin Fierro”. (Photo by Natacha Pisarenko/AP Photo)

In this Thursday, October 5, 2017 photo, Chile's singer-songwriter Mon Laferte performs in concert at the Auditorio Nacional in Mexico City. The 34-year-old artist, who just received five Latin Grammy nominations, performed three sold-out concerts at the National Auditorium, on consecutive evenings, beginning Thursday. (Photo by Eduardo Verdugo/AP Photo)

A picture shows the full moon during a “blood moon” eclipse over the temple of Apollo in Corinth on July 27, 2018. The longest “blood moon” eclipse this century began on July 27, coinciding with Mars' closest approach in 15 years to treat skygazers across the globe to a thrilling celestial spectacle. (Photo by Valerie Gache/AFP Photo)

Cosplayers (left to right) Oli Hazeldine (dressed as Princess Adora from the animated series She-Ra); Val Imms (Catra from She-Ra), and Lou Frewin (Raven from the animated series Teen Titans) travelling on a Jubilee Line train heading for MCM Comic Con at the ExCel London in east London on Sunday, May 29, 2022. (Photo by Yui Mok/PA Wire)

US M142 High Mobility Artillery Rocket System (HIMARS) is launched as journalists film during a military exercise in Capas, Tarlac province, Philippines, 13 October 2022. The Philippines hosted simultaneous combat drills with the United States, South Korea, and Japan to improve interoperability in times of conflict. (Photo by Francis R. Malasig/EPA/EFE)