GEOFF BENNETT: In Europe, a climate crisis is unearthing history.

Months of brutal heat waves have left the Danube River at a critically low level.

But, as the water vanishes, it's revealing relics from the past, including warships and even fossilized bones.

Our Deema Zein has our report.

DEEMA ZEIN: World War II era shipwrecks are emerging as one of Europe's biggest rivers disappears.

Months of heat waves have left the Danube River's water levels at critically low levels, revealing islands, animal fossils, and the remains of sunken warships.

Now, the river is Europe's second longest, flowing through 10 countries and spanning 1,700 miles.

But as the water level falls, World War II era Nazi warships are emerging from the riverbed, revealing a part of history hidden beneath the water for years.

In Serbia, at least 20 of the 200 German ships intentionally scuttled during the war can be seen from the banks of Prahovo, a village located on the river.

Now, while some of the ships had been previously removed by the communist Yugoslav authorities, many remained due to the dangerous explosives on board.

Now, the warships aren't the only historic relics resurfacing from the past.

In Bulgaria, some residents discovered the bones of a woolly mammoth.

The animals coexisted with ancient humans and were hunted for food, tusks and bones before they went extinct.

For "PBS News Hour," I'm Deema Zein.