The storm dumped almost 18 inches of rainfall within an hour and a half, causing rivers to burst their banks and flood waters to sweep away cars with explosive force.
Olbia Mayor Gianni Giovannelli said the city had been destroyed by the “apocalyptic” storm, which washed out bridges and submerged homes beneath 10 feet of water. He described the storm as a “water bomb.”
At least 16 people lost their lives during the flash flooding.
“This is a national tragedy,” Prime Minister Enrico Letta told reporters.
One island resident told La 7 television that he tried in vain to save the lives of a father and his two-year-old son who were holding onto a tree branch in a swollen river.
“The two were crying for help before being swept away in front of my eyes," he said.