Flooding from record rains in the mountainous region that spans France and Italy killed two people in Italy and left at least 24 people missing in the two countries, authorities said on Saturday.
A storm which moved overnight across southeastern France, and then northern Italy caused major flooding on both sides of the border, damaging homes, destroying bridges, blocking roads and isolating communities.
In Italy, a firefighter was killed during a rescue operation in the mountainous northern region of Val d’Aosta.
Another body was found in Vercelli province, near where a man had been swept away by floodwaters late on Friday.
Authorities were searching for 16 people missing in Piedmont region, most of whom had been travelling in cars in the Col de Tende high mountain pass between France and Italy, according to civil protection authorities.
They include two people from Germany driving with their grandchildren – aged 11 and six – and a pair of brothers returning from France.
One man was reported to have been swept away by a swollen river after exiting his car in the province of Vercelli.
Unrelenting rainfall overnight hit levels not seen since 1958 in northern Italy’s Piedmont region, where 630mm (24.8 inches) of rain fell in 24 hours, according to the Italian civil protection agency.
Two brothers were swept away by floodwaters while they were tending animals near the French border. One brother managed to grab onto a tree and was saved, while authorities were searching on the French side for the other brother.
Eleven campers were saved in Vercelli province, where floodwaters hit a 20-year high.
Alpine rescue squads evacuated by foot seven people who were in houses cut off by flooding at Terme di Valdieri; some had to be carried on stretchers due to the muddy conditions and accumulation of detritus.
On the other side of the border, in southeastern France, almost a year’s average rainfall fell in less than 12 hours in the mountainous area surrounding the city of Nice.
Local firefighters said at least eight people were missing, including two firefighters whose vehicle was swept away by water when the road collapsed during a rescue operation. Several dozen people were evacuated from their homes overnight, firefighters said.
The storm, dubbed Alex, ravaged several villages around the city of Nice on the French Riviera. Nice Mayor Christian Estrosi called it the most severe flooding disaster in the area for more than a century after flying over the worst-hit area by helicopter.
“The roads and about 100 houses were swept away or partially destroyed,” he told French news channel BFM.
French President Emmanuel Macron on Saturday expressed his gratitude to the rescuers on Twitter, writing: “Together we will get through this.”
Meteo France said 450mm (17.7 inches) of rainfall had been registered over 24 hours in some areas – the equivalent of close to four months of rain at this time of the year.
There was more rainfall than on October 3, 2015, when floods caused the death of 20 people in and around the French Riviera city of Cannes, Jeremy Crunchant, director of civil protection, told France Info.
Meteo France had issued a danger alert on Friday and all schools in the region had been closed. Local authorities urged people to stay at home.
French Prime Minister Jean Castex and Interior Minister Gerald Darmanin arrived in the area later on Saturday.