A family of three were reportedly among 16 people killed when torrential rain across the French Riviera sparked flash floods that upturned cars, submerged whole streets and inundated homes.

Witnesses on Sunday described how driving “horizontal rain” struck the Côte d’Azur – a record 107mm fell in Cannes in just one hour – along with hailstones the size of ice cubes.

Burst riverbanks sent torrents of water pouring through French towns in the area as a combination of lightning and water damage knocked out elecriticity to tens of thousands of homes.





Facebook Twitter Pinterest French fireman inspect an abandoned car stuck in muddy waters near an underpass in Cannes. Photograph: Eric Gaillard/Reuters

Aerial photographs have revealed the scale of the devastation, with swathes of the Côte d’Azur still submerged in muddy brown water hours after the storm had passed.

Most of the victims died in vehicles, but three elderly residents of a retirement home near Antibes drowned after the river Brague burst its banks and left the ground floor of the building submerged.



A woman was swept away by a wave of water while walking in the street in Cannes on Saturday night, and a driver was discovered drowned in a car in the town on Sunday morning. Another victim died at a camping site at Antibes.



Some ignored warnings to stay at home and, underestimating the strength of deluge, made fatal errors that cost their lives.



At least four people were reportedly trapped by rising water in an underground car park as they tried to save their cars. Meanwhile, the family of three are believed to have perished after ignoring warnings not to drive into the flooded tunnel at Vallauris-Golfe-Juan.

“They pushed through down the road, everyone was saying don’t take that tunnel it’s too dangerous but they carried on,” a witness told BFMTV. The tunnel was still under three to four metres of water on Sunday morning.



When the water ebbed and the fire services pumped out underground car parks and buildings, the bodies were discovered in Cannes, Biot, Golf-Juan and Mandelieu-la-Napoule, west of Cannes.



Eric Ciotti, president of the departmental council, said: “We’ve had catastrophes, but never of that violence”.



The French president, François Hollande, who flew to the region, praised the “exceptional mobilisation” of the emergency services who spent much of Saturday night evacuating homes, camping sites and inundated buildings and pumping out flooded areas.



After visiting the retirement home near Antibes and local businesses, Hollande said the government would officially declare a state of natural disaster at its meeting on Wednesday. This would allow those affected to claim damages and financial support, within three months or sooner, to show the “solidarity of the nation”.



Facebook Twitter Pinterest People look at vehicles under water in Mandelieu la Napoule. Photograph: Sebastien Nogier/EPA

“I wish to express support for the families concerned who are grieving today. I’d like to hail the work of all the rescue services … there has been an exceptional mobilisation given the gravity of the situation,” Hollande said.



“There will be no time lost to give people support and not just moral [support], but for the damage they have suffered. There is anger and discouragement … it’s important people can open their shops and businesses as soon as possible.”



Hollande emphasised the psychological effect on the local population, some of whom lost everything in a few minutes as the water inundated their homes, shops, factories and offices.



“There was fear also, seeing the water rise so suddenly and not be able to do anything about it,” Hollande added.



The area was subject to an “orange” weather alert on Friday when it began raining early in the morning. The weather improved briefly on Saturday morning, but the deluge began again by evening. Weather officials said parts of the region endured 10% of their average annual rainfall in a matter of hours. One local resident spoke of seeing two metres of water fall in less than two hours.



In Mandelieu-La-Napoule, mayor Henri Leroy, said the river swelled by 200 cubic metres in less than two hours, bursting its banks and flooding the town where seven people died, four of them trying to retrieve their cars from an underground car park.



“There were two waves, one between 8 and 9pm and the second between 9 and 9.45pm. They engulfed the lower areas including the garages. Some of our locals tried to save their cars. One woman, whose husband is missing, said he went to get his car out of the garage.

Facebook Twitter Pinterest President Hollande meets people in the flood-affected area. Photograph: Jean-Christophe Magnenet/AFP/Getty Images

“Unfortunately, the wave came and trapped them inside,” Leroy added. “But the water is so cloudy the firefighters cannot see the bodies.”

French weather experts were criticised for not forecasting the disaster but insisted they had issued adequate warnings and admitted they could not have predicted the severity of what they described as “sudden and exceptional” meteorological conditions.

François Gourant of the French weather station Météo France, said: “It’s difficult to say why it happened at this particular time in this particular place. We can predict storms and flooding, but not of this size or suddeness.”

Gourant said an unprecedented 195mm of rain fell in Cannes, 107mm in one hour. The previous record was 70mm in an hour.



“We have no explanations why it happened … the region is used to flooding. It’s an unusual phenomenom,” Gourant added.



Victims, who described how they had lost everything in just 10 minutes, used stronger words to describe their experience and the devastation: catastrophe, the “end of the world” and apocalypse.



Rachael Dickens, who has lived in Valloris for 14 years, said it was like a tsunami.



“I drove down to the coast this morning and there were cars overturned and down holes, and piles of stones and mud. But this is a first world country and everyone was out with their shovels clearing up this morning. There was a big community effort. Within four hours a lot of it had already been cleaned up,” Dickens said.



“The rain was terrifying. We’re used to storms here, but I have never seen anything like it. The rain was sheeting sideways. I live on a hill but there was 3cm of water outside my door. If you were at the bottom there was nowhere to escape. People died getting out of their cars or asleep in their apartments.



“It’s tragic, but so needless. We were all well warned and there was an orange weather alert which is not nothing.”



On the Nice Matin website, a school assistant called Marie, 32, described how she saved a father and his two children who were stuck in their car.

“I heard cries and waded towards the car, which was stuck. It’s headlights were under water. I had water up to my bottom and there was a lot of current. Inside the car was a father and two children who couldn’t have been more than seven and nine. They were trapped. The water was up to the windows and it was impossible to open the door. The motor had stalled and there was no electricity to open the electric windows. We had to force them open. The children were crying in a panic.”

Shelley Ward, a British actor living in the Côte d’Azur, said: “There were hailstones like ice cubes and torrential horizontal rain in Antibes last [Saturday] night. On the roads I saw five accidents, trees were down and rocks and gravel spattered on the roads. There was a bus across the carriageway and scores of cars abandoned by the side of the road.

“It has to be the worst storm I’ve seen down here in 25 years.”



Many roads were still closed late on Sunday evening and train services were still disrupted. Cannes railway station was flooded and about 21,000 homes without electricity. The local education authorities announced that a dozen schools and colleges would be shut on Monday.



The interor ministry said on Sunday there was “little chance of finding those still missing alive”.

