Video showed cars being carried through the streets by the fast-moving currents before midnight local time as nearly 8 inches of rain fell in just three hours.
"We are doing our utmost to deal with this emergency," said Eugenio Giani, the president of the Tuscany region. "We are evaluating all the critical situations reported and working closely with all institutional, health and civil protection levels. I thank the staff of the Municipalities, the operators and the volunteers who are working tirelessly. For our part, attention is and will remain very high until the emergency is over. I am working on an ordinance for the management of waste and excavated soil, to also address this aspect, which is fundamental for the effectiveness and speed of interventions, without neglecting the protection of environmental aspects".
At least two people remain missing as search and rescue operations continue across the region.
Firefighters said they responded to more than 100 calls and performed dozens of rescues, with many drivers caught off guard by the fast-moving water. Four people were rescued after they were trapped in their vehicles when the Tagliamento River flooded, according to Vigili del Fuoco.
About 60 firefighters working with divers and river rescue teams were searching a swollen Rui canal in Puos D’Alpago for a missing firefighter, Vigili del Fuoco reported.
"We have just sent inflatable boats to Seano, Quarrata and Campi Bisenzio," Eugenio Giani, the president of Tuscany, posted on X on Thursday. "We have also asked the National Civil Protection for helicopters for the urgent transport of people in code red."
Matteo Biffoni, the mayor of Prato, said the situation was extremely critical and encouraged residents in the region to find higher ground and not to venture outside their homes during the storm.
The local government proactively closed schools, parks, sporting venues and other facilities ahead of the severe weather that saw winds gusting from 50-70 mph as Ciarán swept by.
Giani said the region had not seen that kind of rainfall in more than 50 years, and it amounted to receiving what normally rains over the entire month of November.
Ciarán's wrath was felt across a wide swath of northern Europe. The storm transformed into a bomb cyclone as it raced across the Atlantic Ocean, eventually reaching a peak strength of 953 millibars and setting a record for the lowest pressure measured in England in November. The storm triggered incredible winds gusting well over 100 mph along France's northwestern coast and left 1.2 million without power.
Overall, at least 13 people have died across Europe in connection with the powerful storm.