The city’s squares and streets turned into lakes as widespread flooding left the city of Catania and its surroundings underwater.
More than 300mm (11.8 inches) of rain – almost half the average amount expected on the Mediterranean island in a year – fell in a matter of hours on Sunday, according to the Sicilian Farmers Association.
The downpours prompted emergency authorities to issue the highest red alert warning for the northern tip of Sicily and Calabria to the south Italy, warning of a potential risk of death and property damage.
A man’s body was found under a car as torrential winds and rains swept through the town of Gravina, north of Catania, volunteer rescuers said.
The body of another man, 67, was found on Monday in a citrus grove far from where his car was hit by rising waters and mud, southwest of Catania.
His wife has been reported missing, emergency services said, as rescuers tackle rapidly deteriorating conditions.
Analysis by Joanna Robinson, Weather Producer
A low pressure system in the central Mediterranean has already brought significant rains, with more heavy rains expected over the next few days.
During the last 48 hours, 199.6 mm of rain was recorded in the region of Calabria, in the southwest of Italy.
Further heavy showers, thunderstorms or longer periods of rain will bring an additional 100-200mm of rain to southwest Italy and Sicily over the next few days.
Up to 250 mm are possible in some places. Flooding is a big concern, with lightning, large hail and gusty winds additional dangers.
Warnings of red rain and thunderstorms cover southwest Italy through Wednesday and Sicily through late Thursday.
According to the Met Office, total precipitation could be more than three times the October average before the low moves northward.
The extreme rainfall comes just weeks after the European 12-hour rainfall record was broken in northwest Italy.
Rossiglione in Genoa, Liguria, saw 741mm of rain fall in just 12 hours on October 4, breaking the European record.
It also follows a summer of flooding in Germany, Belgium, the Netherlands and Luxembourg.
“The emergency situation is generalized and extremely critical and it does not seem to be improving,” warned a spokesperson for the firefighters.
The mayor of Catania, Salvo Pogliese, ordered the closure of all stores, except pharmacies and grocery stores, until midnight.
“I urge all people not to leave their homes except in an emergency,” he wrote in a Facebook post on Tuesday.
Flood waters also hit a ward at Garibaldi Hospital in Catania, according to local media.
Power outages were triggered in the city center while a number of schools were also forced to close.
Dozens of flights have been diverted from the region and ferry connections between the southern islands have been canceled.
The tropical-type storm is believed to be a medicine, sometimes referred to as a Mediterranean cyclone or hurricane.
The devastating weather system – which is expected to peak between Thursday and Friday – struck when the sea was 8 ° C warmer than average, according to Italian weather site Ilmeteo.it.
It occurs just a few weeks after more than 29 inches of rain poured over Italy in just 12 hours – break a European record, with the municipality of Rossiglione in Genoa, in Liguria, among the most affected areas.