A freak torrential rainstorm has killed at least 17 people in Sardinia, wrecking bridges and sweeping away cars.
Italian premier Enrico Letta declared a state of emergency and set aside 20 million euros (£17 million) for emergency relief, saying the priority was reaching remote areas, saving the lives of those still unaccounted for and providing for those left homeless.
The island, which draws royals, entrepreneurs and ordinary tourists alike during the dry, peak summer months, received more than 17 inches of rain in 24 hours on Monday - half the amount it normally receives in a year.
Italy's civil protection chief, Franco Gabrielli, said the death toll may rise as teams reach isolated areas in the countryside where some homes are submerged.
Transport was hampered by rivers of mud gushing over roads that forced the closure of several major routes, including a tunnel into the city of Olbia.
Olbia mayor Gianni Giovannelli said the city had been destroyed by the "apocalyptic" storm, with bridges felled and water levels reaching 10 feet in some places. He described the ferocity of the rains as a "water bomb."
Mr Gabrielli defended the civil protection's alert system, which had signalled an "elevated" risk of the storm on much of Sardinia, the highest level of alert. He warned against day-after finger-pointing, saying evacuation orders had been issued and ignored and that no weather forecast could have predicted the "exceptional" degree of devastation.
A family or four, originally from Brazil, were among the dead. A policeman helping to escort an ambulance died when the car he was travelling in was submerged in the collapse of a bridge in Dorgali. In hard-hit Gallura, three people died after their car was swept away in the collapse of another bridge.
Other parts of Italy were also hit by heavy rains, including Rome, and Venice in the north, where tourists had to slosh through a St. Marks' Square flooded from the "acqua alta" high tides that periodically submerge the city.