At least 18 people have been killed and 40 injured after rainstorms in Sicily washed away roads and destroyed homes around Messina.
A further 20 people are missing, with rescue workers digging through the mud to find survivors.
Some people took refuge on roofs and were plucked to safety by helicopter.
One man died, trapped in his car when it was hit by a torrent of water and mud, while another man survived after climbing out of his submerged vehicle.
Messina Mayor Giuseppe Buzzanca said his town had been cut off by rain and mud which had blocked roads and covered railway lines, so the injured were being moved by sea.
He urged doctors, nurses and volunteers to go to the stricken zone to help.
The national government declared a state of emergency as a result of the heavy rains, which began late yesterday and grew more intense overnight.
Rescue services chief Guido Bertolaso, at a news conference to detail the number of victims, said the impact of the rain and mud was made much worseby the spread of dangerously unregulated building, which is very common in southern Italy.
The environmentalist group Legambiente said the island was ‘paying a very high price for destroying the land with huge, unregulated blocks of cement’.
The city of Messina would be the site of one end of a controversial €10bn bridge linking mainland Italy to the Mediterranean island which the government says will be completed by 2016.