On the night of 3–4 November 1966, exceptionally heavy rain caused the Arno to burst its banks and flood Florence. The disaster claimed 35 lives in Tuscany and left the regional capital buried in mud, with the flood described as carrying around 600,000 tons of it into the city.
Flooding began in the Casentino valley before surging through the Valdarno. The river gathered more water as it met the Sieve, and reached Florence while many residents were asleep ahead of the 4 November public holiday. In the early hours, the Mugnone overflowed and the Arno broke its banks at several points. Power failed, disrupting phone, water and gas services, while roads, rail lines and bridges became impassable.
Water and sludge mixed with heating oil and debris, flooding homes and streets. By 10 a.m., water had reached the first floors of buildings. The deluge swept through Piazza del Duomo and damaged the Baptistery’s Gates of Paradise. The National Central Library and the church of Santa Croce were also inundated.
The flood caused extensive damage to Florence’s cultural heritage. At the National Central Library, 1.3 million books were underwater; the Vieusseux Cabinet lost 250,000 volumes, while the Georgofili Academy and Great Synagogue had 35,000 and 14,000 books affected respectively. Cimabue’s Crucifix in Santa Croce was devastated, and frescoes and artworks in several other churches were damaged.
When the water began to recede on the evening of 4 November, it left streets blocked by rubble and buildings marked by a dark line showing how high the flood had reached. The account also points to later floods across Tuscany and argues that lasting protection requires structural measures and rules that are followed, rather than relying repeatedly on volunteers.
Sources: La Repubblica.