Hurricane-force winds, surging seas and driving rain lashed western Europe yesterday, leaving at least 52 people dead and more than a million households without power.
Dubbed "Xynthia", the Atlantic storm crashed against the western coasts of France and Spain, bringing with it a band of foul weather stretching from Portugal to the Netherlands and inland as far as Germany.
The bulk of the casualties were in France, where gusts of 150 kilometres per hour and eight-metre waves battered the west coast, flooding inland and sending residents scurrying onto rooftops.
Prime Minister François Fillon said France would formally declare the storm a natural disaster, thus freeing up funds to help communities rebuild.
"We were warned, but I didn't think it could do this," said 62-year-old retiree Jean-François Dikczyk, who saw the sea surge several hundred metres inland and smash though the windows of his house.
"My mother was nearly killed. She's 83 and disabled. She was sleeping on the ground floor, and her mattress was floating. My son and I managed to get her upstairs, but it was really catastrophic," he said.
In the western town of La Faute sur Mer, householder Jean-Pierre was left barefoot and homeless. He and his wife woke in the night to find water rising up the stairs, filling the house in less than half-an-hour.
They climbed onto the roof and waited eight hours to be rescued. All the while the shutters on the house of their elderly neighbours remained shut.
"We don't know what happened to them," he said, visibly in shock.
In all, 45 people have been confirmed dead in France since Saturday, according to the interior ministry.
Most of those lost were drowned in the flooded coastal towns of the Vendée and Charente-Maritime regions.
Some boat owners ignored warnings and stayed onboard overnight in west coast marinas. "The boat was rolling so much it was like being on the ocean," said 60-year-old Robert Monne, who came ashore to find his car swept away.
Emergency services plucked families from rooftops with helicopters and rescue launches, and hundreds of refugees sought temporary accommodation.
Shortly after 5 p.m. state forecaster Meteo France said the storm had passed into Germany, Belgium and the Netherlands, and there were reports of high winds in the Swiss Alps.
In Germany, a motorist in the Black Forest and a female jogger in the western town of Bergheim were killed by falling trees.
In Spain, regional authorities said yesterday that two men aged 51 and 41 died when their car was hit by a falling tree. An 82-year-old woman was killed on Saturday when a wall collapsed in the Galicia region.
Portugal said on Saturday that a 10-year-old boy was killed by a falling branch and flood waters continued to rise on Sunday.
The northern cities of Porto and Vila Nova de Gaia issued flood warnings as the Douro river threatened to break its banks.
A man in his 60s was killed by a falling tree in Belgium, and emergency services were called out repeatedly to deal with fallen power lines.
In France, fallen power lines caused blackouts for around a million homes across a 500 kilometre swathe of the country from the Brittany peninsula to the highlands of the Massif Central.
The national power firm EDF said half a million clients were still without power at nightfall on Sunday, and Fillon said it would take several days to restore power everywhere.
Air France said 100 flights out of 700 were cancelled from its hub at Paris Charles de Gaulle, where an AFP reporter saw sections of one terminal roof starting to come loose.
Europe 1 radio reported wind speeds of 175 kilometres per hour at the tip of the Eiffel Tower in Paris, but Xynthia fell short of the record 200-kph levels of a deadly 1999 storm system, which killed 92 people.