Italian Prime Minister Matteo Renzi led tributes to the "Angels of Mud" Friday to thank the 10,000 volunteers who saved pieces of art in a 1966 Florence flood.

"Your optimism and your energy leads us to look to the future with enthusiasm," said Renzi, who also served as mayor of Florence between 2009-2014.

The Arno river burst its banks exactly 50 years ago Friday and destroyed countless pieces of art and literature in the city that played a crucial role in the Renaissance. About 100 people died in the flood.

One of the most remarkable rescues was of 16th-century artist Giorgio Vasari's "The Last Supper." The painting depicted the scene in the Bible in which Jesus Christ shared his final meal with his apostles. Though it was saved from the flood, the piece was long considered impossible to restore and left in storage for four decades. But in 2006, the Italian arts restoration agency Opificio Delle Pietre Dure (OPD) determined restoration was possible with new technology. After two years of study, a team of 13 experts went to work to restore the artwork. The restored work was unveiled to the public in the Basilica of Santa Croce as part of Friday's ceremonies.

"In the beginning, everyone said it was impossible to restore. It was a long battle but we made it," said OPD Superintendant Marco Ciatti. To prevent damage, the painting is now attached to a mechanism that raises it up in the event of future flooding.

(DW)