At least 13 people are known to have died on Sunday night as flash floods swept through villages around the southern French city of Carcassonne, according to the interior ministry’s rescue service.
In the village of Villegailhenc, the river Trapel swelled to such an extent that it swept away at least one road bridge.
French emergency service personnel were out in area rescuing people from the floods.
All this happened suddenly and in the hours of dark as the tropical remains of Leslie were lifted over the eastern Pyrenees and the Haut Langedoc.
A spell of torrential rain resulted, with Carcassonne recording 70mm of rain in just three hours. The long-term average rainfall for October in Carcassonne is 60mm and in the last 24 hours alone, 140mm have been collected.
Local reports describe waters rising by seven metres in a few hours and people scrabbling onto their roofs to await rescue. Flooding is not uncommon in this region when thunderstorms grow over the high ground, and flash-flooding down the valleys is often destructive. However, this could be the worst event for 20 years.
The French weather service, Meteo France, issued a warning of flood risk for all surrounding departments for 24 hours.
Over the next few days the flood risk remains with northeast Spain, southern France, Corsica and Sardinia at risk.