At least 120 people have died and hundreds more in western Europe are unaccounted for after some of the worst flooding in decades.
Record rainfall caused rivers to burst their banks, devastating the region.
In Germany, where the death toll now stands at over 100, Chancellor Angela Merkel called for a determined battle against climate change.
At least 20 people have died in Belgium. The Netherlands, Luxembourg and Switzerland are also affected.
Many factors contribute to flooding, but a warming atmosphere caused by climate change makes extreme rainfall more likely.
The world has already warmed by about 1.2C since the industrial era began and temperatures will keep rising unless governments around the world make steep cuts to emissions.
Belgian Prime Minister Alexander De Croo declared 20 July a national day of mourning.
“We are still waiting for the final toll, but this could be the most catastrophic flooding our country has ever seen,” he said.
We met an elderly man trying to get into a village which was all but destroyed. His grandchildren were there, he said, but he couldn’t get hold of their parents.
Even the authorities say they don’t know for sure how many people are missing. There is no phone signal in much of the region, making communication all but impossible. But the death toll is expected to rise today and with every hour that passes the magnitude of this disaster becomes ever clearer.
All along the River Ahr there are flooded homes, broken bridges, the twisted remains of campsites and caravan parks. For many of the dazed people we met surveying the damage here, it’s almost impossible to imagine clearing up and starting again.
Some 15,000 police, soldiers and emergency service workers have been deployed in Germany to help with the search and rescue.
Entire villages have been destroyed, and officials in the western German district of Ahrweiler say up to 1,300 people are unaccounted for.
Gregor Jericho, a resident of Rheinbach in North Rhine-Westphalia, told the BBC: “It’s a very sad scene. Streets, bridges and some buildings are destroyed. There’s garbage everywhere.
“Parts of buildings are in the road, people are sitting and crying. It’s so sad. People have lost their homes, their cars are in fields flooded. My city looks like a battle has taken place.”
