In pictures: The collapse of Ukraine's Nova Kakhovka dam

The Nova Kakhovka dam in southern Ukraine collapsed early Tuesday, June 6, forcing more than 1,400 people to flee their homes and threatening vital water supplies as flooding inundated the region.

Kyiv and Moscow have traded accusations over the Russian-occupied dam's destruction, without providing concrete proof that the other is culpable. It is not yet clear whether the dam was deliberately attacked or whether the breach was the result of structural failure. 

Ukrainian President Volodymyr Zelensky described the situation as "an environmental bomb of mass destruction," as concerns turned to the dangers to wildlife, farmlands, settlements and water supplies from the floodwaters and possible contamination from industrial chemicals and oil leaking from the hydropower plant into the Dnipro River.

The critical dam is the largest reservoir in Ukraine in terms of volume. It's the last of the cascade of six Soviet-era dams on the Dnipro River, a major waterway running through southeastern Ukraine. There are multiple towns and cities downstream, including Kherson, a city of some 300,000 people before Moscow's invasion of its neighbor.