Much of Venice was left under-water after the highest tide in 50 years ripped through the historic Italian city, beaching gondolas, trashing hotels and sending tourists fleeing through rapidly rising waters.
Italy was poised to declare a state of emergency for Venice after an exceptional tide surged through churches, shops and homes, causing millions of euros worth of damage to the UNESCO city.
Thoroughfares were turned into raging torrents, stone balustrades were shattered, boats tossed ashore and gondolas smashed against their moorings as the lagoon tide peaked at 187 cm (6ft 2ins) shortly before midnight.
It was the highest level since the record 194 cm set in 1966 but with rising water levels becoming a regular threat to the tourist jewel, city mayor Luigi Brugnaro was quick to blame climate change for the disaster.
"Venice is on its knees," said Brugnaro. "The damage will run into hundreds of millions of euros."
"This is the result of climate change," he said on Twitter.
The floods, accentuated by driving rains and strong winds, also ravaged areas beyond the city itself.
One man died on Pellestrina, one of the many islands that dot the Venetian lagoon, electrocuted while trying to pump water out of his house.
"Venice has been tortured, but there are also other parts of the Veneto region besides Venice. It is an apocalyptic disaster," regional governor Luca Zaia told reporters.
Venice's huge Saint Mark's Square, once described as Europe's living room, was submerged by more than one metre of water, while the adjacent Saint Mark's Basilica was flooded for the sixth time in 1,200 years - but the fourth in the last 20.
"The Basilica is suffering structural damage because the water has risen and so it's causing irreparable damage," said Venice Archbishop Francesco Moraglia, warning that ancient mosaics and tiling might have been badly degraded.
A flood barrier was designed in 1984 to protect Venice from high tides, but the multi-billion euro project, known as Mose, has been plagued by the sort of problems that have come to characterise major Italian infrastructure programmes -- corruption, cost overruns and prolonged delays.
Originally expected to start operating in 2011, the city now expects it to be functioning in 2021.