The storm, called Alex, ravaged several villages around the city of Nice on the French Riviera. The mayor of Nice, Christian Estrosi, called it the worst flood disaster in the region in more than a century after he flew over the worst affected area by helicopter.
“The roads and a hundred houses were washed away or partially destroyed,” he told French news channel BFM.
At least eight people were reported missing in France, authorities said. These include two firefighters whose vehicle was swept away by a swollen river, according to local witnesses cited by several French media.
In Italy, at least one person has died and up to 11 people are missing, local authorities said.
Six German hikers were among the missing after failing to return from a trip to the mountains of Cuneo province.
Officials in the Piedmont region reported a record 630 mm (24.8 inches) of rain in just 24 hours in Sambughetto, near the border with Switzerland. Piedmont regional leader Alberto Cirio called on the government to declare a state of emergency.
TV footage shot in Italy showed that several roads and bridges in the country’s northwest were washed away by floodwaters and many rivers were said to have burst from their banks.
Eric Ciotti, a member of the French parliament from one of the region’s most affected villages, Saint-Martin-Vésubie, said several villages had been cut because they are located in the steep valleys of the mountainous region.
Meteo France said rainfall of 450 mm (17.7 inches) of rain was recorded over 24 hours in some areas – the equivalent of nearly four months of rain at this time of year.
There was more rainfall than on October 3, 2015, when flooding killed 20 people in and around the city of Cannes on the French Riviera, Jérémy Crunchant, director of the French Riviera, told France Info. civil protection.
Venice, a long-delayed flood barrier system, managed to protect the lagoon city from a high tide for the first time on Saturday, bringing great relief after years of repeated flooding.