Heavy floods have forced the evacuation of 1,600 people, most of them campers in Southern France, officials say.
They say a 70-year-old German man who was helping to supervise children at one of the summer camps is missing.
The worst-hit areas are Gard, Ardeche and Drome. More than 400 firefighters and police as well as four helicopters have been deployed.
The storms which caused the floods come after a period of unusually hot weather in Southern France and much of Europe.
According to UK Meteorological Office, Marco Petagna, almost 3in (8cm) of rain fell in a 24-hour period.
In a statement (in French), the French Interior Ministry said six departments had been placed on a flood alert, while about 17,000 homes were without power in the Southwest and Northeast.
In one summer camp in Saint-Julien-de-Peyrolas, in the Gard region, 119 children were evacuated.
The missing German was supervising the children at the camp.