Danube's record low water reveals WWII warships and threatens nuclear power plants

A record-low water level in the Danube, caused by extreme heat, has exposed sunken German warships from World War II. Rusted hulls and broken masts are now visible mid-river near the Serbian port of Prahovo, which marks the border between Serbia and Romania.

The vessels belonged to Nazi Germany's Black Sea fleet. According to the Associated Press, they were deliberately scuttled in September 1944 as German troops retreated from Romania under pressure from the Soviet army. Historians estimate that up to 200 ships were sunk in the gorge near Prahovo, an operation intended to slow the Soviet advance into the Balkans.

The receding waters have brought other discoveries. In Bulgaria, bones found on the riverbed are believed to belong to a woolly mammoth from the Ice Age. In Romania, an underwater rock formation was blasted to redirect cooling water to the country's only operational nuclear reactor. Romania and Hungary have for the first time shut down reactors cooled by the Danube, raising fears of an energy crisis driven by drought.

Scientists link Europe's extreme weather to climate change. Richard Allan, a professor of climatology at the University of Reading, told CNN that current hydrological anomalies are just the beginning: as warming continues, water management will become more challenging and extreme events more frequent.