Ukraine marked the 40th anniversary of the Chornobyl disaster. Officials voiced significant fears that Russia's ongoing war could trigger a repeat of the devastating nuclear accident.

<img alt="People in hazmat suits place candles and flowers at a memorial." height="349" src="https://i.cbc.ca/ais/07019beb-258b-41ba-bea2-679aeed46ded,1777231560942/full/max/0/default.jpg?im=Crop%2Crect%3D%280%2C75%2C6048%2C3402%29%3BResize%3D%28620%29" title="TOPSHOT - Participants dressed in white hazmat suits, representing liquidators, place candles in front of a memorial for Chernobyl victims, during a commemoration ceremony marking the 40th anniversary of the explosion at the Chernobyl nucl...