People walk in the flooded Riva degli Schiavoni in front of the San Giorgio church. Image Credit: AFP

Venice: Venice was inundated by an exceptional high tide Monday, putting three-quarters of the famed Italian lagoon city under water as large swathes of the rest of Italy experienced flooding and heavy winds that toppled trees and other objects, killing six people

Two people were killed when a tree fell on their car not far from Rome, and a young man in the Naples region also died after being hit by a falling tree, according to authorities.

In Venice, rain-soaked tourists were barred from an inundated St. Mark's Square where local authorities said the "acqua alta" (high water) peaked at 156 centimetres (61 inches) by early afternoon, the elevated wooden platforms, usually placed on main passageways in the Renaissance city were not enough to ensure safe passage in the low-lying square.

Officials closed major tourist attractions in Rome, including the Colosseum and Roman Forum, early because of heavy rains.

Families carried children on their shoulders through the surrounding streets. While some tourists donned thigh-high wellies, others had opted to take off their shoes and wade through the water.

Pictures: 75% of Venice under water in record-breaking floods

The waters have only topped 150 centimetres five times before in recorded history. In 1966, when floods swept through the country, famously devastating Florence's historic centre, the waters reached 194 centimetres in Venice.

Corruption scandals

Nearly all of northern Italy was on alert due to the violent storms with wind gusts up to 100 kilometres per hour and the rainfall in some places equivalent to the amount of rain that falls over several months.

Much of Italy is under alert for flooding from heavy rains, a problem exacerbated by a lack of maintenance of the country's many river beds. 

Venice Mayor Luigi Brugnaro said a series of underwater barriers that are being erected in the lagoon would have prevented the inundation. The project, nicknamed Moses, is long overdue, beset by cost overruns and corruption scandals.

Brugnaro said he had asked to talk with Premier Giuseppe Conte to underline the urgency of the project, which would raise barriers when the tide reaches 109 centimeters (43 inches). That happens, on average, four times a year in Venice.

Situation to worsen

Luca Zaia, head of the Veneto region, said he was worried that the situation could be worse than the huge floods in 2010.

"The ground is already saturated with water, the rivers are full and due to sirocco (a strong hot wind from Northern Africa), the sea is not absorbing (the waters), he said.

In the north all the schools in Veneto were closed as well as in Genoa and Rome.

Veneto regional governor Luca Zaia says flooding this week could reach the levels of the 1966 flood that struck both Venice and Florence. The Interior Ministry urged officials in storm-struck regions, about half of the country, to consider closing schools and offices for a second day Tuesday.