The Chernobyl power plant, which suffered a reactor meltdown in 1986 that left dangerously high radiation levels in the area, was the site of one of the first face-to-face confrontations in the Ukraine War. Russian forces won that battle, taking control of the reactors and raising concerns throughout Europe about their stewardship of them.

Recent reports show just how real those concerns were.

While the Russian army has occupied the Chernobyl plant, Ukrainian workers remain stationed there and overseeing the site’s safety protocols. Around 200 employees were still at Chernobyl as of March 7, according to the BBC, where they have continued carrying out duties despite limited food and medical supplies. Chernobyl workers are usually rotated out regularly, but since the Russian occupation employees have had to endure dangerous weeks-long shifts.

Two of these employees have reportedly witnessed instances of rash and dangerous conduct by the Russians, according to Reuters, with one source calling their behavior “suicidal.” Some soldiers had reportedly never heard about the disaster that some historians believe signaled the beginning of the end for the Soviet Union.

Shortly after the occupation started, Ukrainian officials warned that radiation levels at Chernobyl were rising due to a large number of heavy military machines disturbing the topsoil around the area. These reports have now been confirmed by employees working at Chernobyl around the time of the invasion who observed “a big convoy of military vehicles” driving straight through zones so contaminated with radiation that even trained safety workers at Chernobyl are not allowed to venture there.

Russian armored vehicles without radiation protection were seen driving through an area called the “Red Forest,” an area of woods four square miles in size surrounding the power plant. The area absorbed so much radiation from the Chernobyl explosion that its trees turned a gingery brown color, giving the forest its nickname. It is considered one of the world’s most radioactive places.

The employees said that the military vehicles kicked up a “big column of dust,” which may be what sent radiation levels soaring in the area following the invasion. The workers believed that breathing in that much radioactive dust could cause radiation poisoning, which can quickly turn lethal. 

Valery Seida, the acting general of Chernobyl, has not been at the power plant since the invasion and could not verify the reports, but did confirm several witness accounts of recklessness by Russian soldiers who “drove wherever they needed to,” without heeding the warnings of plant safety officials.

The Russian army has made occupying nuclear power plants a common practice during its campaign in Ukraine. Around a week after taking Chernobyl, Russian forces took over the Zaporizhzhia plant, Europe’s largest nuclear plant, in southern Ukraine.

Ukrainian and Western officials have said that keeping radiation levels at nuclear power plants contained is of paramount importance. In a nearly two-hour call earlier in March, French President Emmanuel Macron spent most of the conversation with Russian President Vladimir Putin discussing safety protocols at Chernobyl and other nuclear power plants in Ukraine.

Since being taken by Russian forces, Chernobyl has lost electrical power multiple times, which Ukrenergo, Ukraine’s electrical grid operator, has said could impair the plant’s safety and containment protocols.

Ongoing military activity in the area surrounding Chernobyl has continued well into March. Last week, the International Atomic Energy Agency warned that Russian shelling near the plant was preventing workers from rotating their shifts after nearly weeks of continuous work, endangering the plant and its safety protocols.