Flooding rages across Germany and Belgium, killing at least 63 amid torrential rains

At least 58 people died in Germany, by far the worst-hit country, where whole villages were cut off from rescuers and helicopters ferried were deployed to pluck the stranded off rooftops. Some houses were simply washed away as a tributary of the Rhine burst its banks.

As night fell, there were fears the death toll could still climb, with dozens still unaccounted for.

Thousands bedding down for the night in makeshift shelters at gyms or with relatives after being evacuated from their homes over concern that, with more rainfall threatening, flooding could spread and dams could collapse.

At least five people were killed in Belgium, prompting the prime minister to appeal for international aid. Severe flooding also impacted the Netherlands, Luxembourg and Switzerland, and warnings were issued in more than a dozen regions of France.

Speaking from Washington, where she is on an official visit to meet with President Biden, German Chancellor Angela Merkel said that words such as "heavy rain" and "flood" were insufficient to describe the level of tragedy.

"In these hours, peaceful places are experiencing a catastrophe," she said, describing her shock at seeing reports of people stranded on rooftops in extreme need.

"I mourn those who lost their lives in this disaster," she said. "We don't know the number yet. But there'll be many."

Some people drowned in the cellars of their houses, she said, and firefighters died while trying to rescue those stranded.

The extraordinary deluge of rain - at levels not seen in the area in the summer for at least 100 years - triggered calls to speed up action against climate change and boost flood protection amid erratic weather events. It came just a day after the European Union announced ambitious plans to reduce net greenhouse gas emissions by at least 55% below 1990 levels within less than a decade.

In the worst-hit parts of Germany, the rainfall in just 24 hours was double the normal long-term average for the entire month of July, according to the Deutscher Wetterdienst, Germany's meteorological agency.

At least 28 people died in the state of Rhineland-Palatinate, authorities said. A region known for its wine growing, villages along the Ahr valley were swallowed by flood waters. As many as 18 people died in the district of Ahrweiler, police said. Earlier in the day, local police said that as many as 50 residents were trapped on the roofs of their homes awaiting rescue.

Videos showed city streets turned into swirling rivers and others engulfed by landslides. Cars were scooped up and tossed aside in crumpled wrecks. From the air, some villages appeared to have almost completely disappeared, only the tops of houses poking out from the floodwaters.

"Entire villages are flooded," Malu Dreyer, the premier of Rhineland-Palatinate, one of the German states most devastated by flooding, said in a speech to the local parliament. "Houses float away just like that."

Helicopters have been deployed for rescues, she added.

Police created a hotline for residents to report missing people, as rescue boats struggled to reach the area due to strong currents. "The consequences are devastating, and our first priority is still to save lives," Jürgen Pföhler, the county commissioner of the Ahrweiler district said at a news conference. "All our efforts are concentrated on that."

The area was declared a disaster zone.

In neighboring North Rhine-Westfalia state, the death toll had climbed to 30, according to the state's interior ministry. The army deployed tanks and trucks to the city of Hagen, where three of its bridges were destroyed, to clear roads of rubble and debris.

In the western state's district of Euskirchen, authorities said at least 15 people were killed. More than 4,500 people were evacuated from a string of villages after experts deemed a nearby dam unstable.

Emergency responders in the city of Solingen rescued about 130 people. "We got people out with aerial ladders, boats, buoys. It was all improvised," a spokesman for the fire department told German news channel WDR.

Two firefighters sent to assist those trapped by rising waters in the Sauerland region died, according to the German news agency DPA.

The country's biggest power distribution company, Westnetz, estimated Thursday that around 200,000 homes were without electricity as a result of the widespread flooding.

On Wednesday, the German weather service issued an extreme weather alert - a warning that environmental expert Bernd Mehlig said was "completely unusual in summer."

The deluge unfolded as a plume of deep moisture, sourced from the Mediterranean, surged into central Europe.

A high-pressure zone over the eastern Atlantic, offshore France and the United Kingdom acted as a pump, steering the moisture plume through France into Belgium, the Netherlands and Germany.

That was flanked by an unusually intense zone of low pressure to the east over central Europe, which helped generate the downpours.

The low was sandwiched between another area of high pressure over Eastern Europe, creating a weather system traffic jam that has allowed heavy rain to persist.

Computer models showed moisture levels in the atmosphere were comparable to those seen along the U.S. Gulf Coast during hurricane landfalls.

The exceptional intensity of the rainfall is consistent with what scientists anticipate with rising temperatures caused by human-induced climate change. Fred Hattermann, a hydrologist at the Potsdam Institute for Climate Impact Research, said such flooding incidents are happening "more often and more intensely" due to climate change.

The duration and frequency of such floods is likely to increase, he said. "What I fear most is that we will see things we never imagined."

A warmer atmosphere can hold more moisture, which then comes down as heavy rain, said Hattermann.

Higher temperatures also speed up evaporation, placing more water in the atmosphere for the kind of downpours that have occurred. A recent study in the Journal of Climate anticipates "large magnitude increases" in extreme precipitation in much of Europe in the coming decades.

While some commentators said it was a taste of the "new normal," climate activist Greta Thunberg said there would be worse to come.

"This is not 'the new normal,'" she wrote on Twitter. "We're at the very beginning of a climate and ecological emergency, and extreme weather events will only become more and more frequent."

Hannah Cloke, a professor of hydrology at the University of Reading in Britain, said warning signs abounded. "Forecasters could see this heavy rain coming and issued alerts early in the week, and yet the warnings were not taken seriously enough and preparations were inadequate," she said.

"For so many people to die in floods in Europe in 2021 represents a monumental failure of the system," she added. "These kind of high-energy, sudden summer torrents of rain are exactly what we expect in our rapidly heating climate. The fact that other parts of the Northern Hemisphere are currently suffering record-breaking heat waves and fires should serve as a reminder of just how much more dangerous our weather could become in an ever-warmer world."

Steffen Seibert, a spokesman for the German government, said the severe flooding was "terrible."

"Even though not every event, not every flooding or local incident, is related to climate change, many scientists tell us that the frequency, the intensity and the regularity with which this happens is a consequence of climate change," he said.

Armin Laschet, the leader of the state of North Rhine-Westfalia who is vying to take over from Merkel in September elections, said more preparations for such extreme weather events are needed.

"We will be faced with such events over and over, and that means we need to speed up climate protection measures, on European, federal and global levels, because climate change isn't confined to one state," he said.

Parts of the Netherlands were also flooded, with a red code warning issued for Limburg province. Local media reported that many people were forced to evacuate and as many as 400 homes were without power.

Switzerland also issued travel and weather warnings this week as heavy rainfall and thunderstorms brought flooding to the city of Zurich.

The mayor of Liege in Belgium said those among its 200,000 residents who could leave the city should do so and that those who could not should move to the upper floors in their homes. One person died in the city and four others were killed in the Belgian district of Verviers.

Earlier this week in Britain, flash floods sparked widespread travel chaos, with parts of London experiencing a month's worth of rain in just one day. Locals were evacuated and cars became trapped as floodwaters continued to rise. Late last month, a tornado swept through the Czech Republic, killing at least five people - an extremely unusual weather event for Central Europe.

Floodwaters in some areas began to recede later Thursday, but it was too early to assess the full toll of the flooding, with some areas still cut off from rescuers.

Yvonne Glasner from Dernau, in the Ahr valley, told Germany's Die Welt newspaper that her family was forced to abandon their newly constructed home.

"We could never have imagined that the water would rise so quickly and so extremely," she said. "Now we are worried that we won't be able to live in our new house at all."

She said that she had not been able to contact her in-laws for hours but had seen their car float past. She said she hoped they were awaiting rescue on a rooftop.