Street in Florence falls into crater on banks of river Arno

No injuries but 20 parked cars swallowed by hole apparently caused by burst water pipe

Residents of Florence woke up on Wednesday morning to find the city had been hit by a spectacular road collapse, on the banks of the river Arno in the tourist heart of the town.

A huge hole, about 200m long and 7m wide, opened up on the riverside, just 100m downstream from the celebrated Ponte Vecchio and across the river from the Galleria degli Uffizi, home to works by Renaissance masters such as Leonardo da Vinci and Michelangelo.

Fortunately, given the time of the incident, no one was injured, but the collapse swallowed about parked 20 cars. One of the first tasks in the clean-up involved the use of cranes and pick-up trucks to haul the cars out the crater.

The cause of the incident has yet to be clarified but it appears to be related to the bursting of a large water pipe that runs underground along the river bank. The water that poured out of this broken pipe for hours, unseen, appears to have washed away the earth. In effect, the burst pipe may have caused a landslide which led to the total collapse of the riverbank street.

Local residents claimed that late on Tuesday night there were flooding problems in the area, probably caused by the original pipe burst. Although the first emergency repairs to that water loss appeared to have resolved the problem, in fact they may have exacerbated it by putting undue pressure on the rest of the water system. The road collapsed at 6.30am, probably after having experienced underground flooding all night.

The mayor of Florence, Dario Nardello, told reporters it was too early to say exactly how the incident had happened. He also stressed there had been no structural damage to the banks of the Arno.

Firemen and civil protection experts also reported that, thus far, none of the many Renaissance palaces and houses that line the Arno at that point had suffered any damage.

The incident quickly became politicised, with government critics suggesting the collapse was the result of four years of incompetent local government by Matteo Renzi, who served as mayor of Florence from 2009-14, prior to his appointment as prime minister.