Updated at 2:55 p.m. ET

"Venice is on its knees," Mayor Luigi Brugnaro says as the lagoon city suffers through some of the worst flooding in its history. The highest tide in 50 years has brought seawater that is threatening monuments and works of art in the historic city.

With more than 85 percent of the city flooded, Brugnaro says the city is in a state of emergency and that he has asked Italy's government for help.

Water driven by strong winds and storms overwhelmed seawalls and smashed brick docks, shoving boats into streets and leaving parts of landmarks such as St. Mark's Basilica and La Fenice Opera House underwater. Although the crypt at St. Mark's has been flooded, a member of the management board tells Italian news agency ANSA the main concern is that water may have damaged the basilica's support columns.

Manuel Silvestri / Reuters

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Reuters

At least one death has been reported: "A 78-year-old man was electrocuted due [to] a short circuit, apparently linked to the flooding" in his home, ANSA reports.

"These are the effects of climate changes," Brugnaro said via Twitter as he surveyed the damage to Venice on Tuesday night.

The high tide inflicted "a wound that leaves indelible marks" on the low-lying city, the mayor said. As of late Tuesday, the high-water mark had reached 6-feet, 2-inches – just 2 inches below the highest flooding ever recorded in Venice in 1966.

Luigi Costantini / AP

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AP

The canal city often experiences its most severe tidal flooding — or acqua alta — in the winter, when strong winds funnel water in from the northern Adriatic Sea. The 1966 high-water mark was also set in November.

"A long and dramatic night for Venice," the city said on its Facebook page. It added that the flooding is comparable only to the 1966 flood.

"Built centuries ago on tiny islands, the city has always been subject to flooding," NPR's Sylvia Poggioli reports from Rome. "An ambitious project of movable undersea barriers called MOSE is yet unfinished due to cost overruns and corruption scandals. Experts say once completed, it will be insufficient to deal with rising sea levels."

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Getty Images

Poggioli tweeted several videos sent from Venice by her niece, who is attending college in the city. One piece of footage shows water rushing out of a toilet, seemingly driven back through the pipes by the floods.

University student Anna Vianello says she and her classmates hurried home early Tuesday night, after noticing water coming in from the sea. A few hours later, she says, things got worse.

"I could see from my window people walking and they had water up to their knees," Vianello tells Poggioli. She adds, "And all the windows were shaking because of the wind."

South of Venice's scenic canals and historic district, the long, narrow beach resorts of Lido and Pellestrina are also being hit hard by flooding, according to Italy's fire and rescue agency, Vigili del Fuoco.

The agency says its employees have been working non-stop to set up barriers and remove water on Pellestrina, using high-capacity pumping modules that have a suction rate of 50 cubic meters of water (more than 13,000 gallons) per minute.

Because of the high water and strong winds from a winter storm, Venice has lost nearly a third of the 1,100 raised walkways it relies on to help people navigate through high water, according to the city's public utility, Gruppo Veritas.

Venice's weather forecast office says that while the worst of the flooding might have passed Wednesday, the tide will stay at "very high" levels in the coming days.

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