The Italian Transport Minister visited the scene of the deadly Genoa bridge collapse today, furious, threatened heavy fines for the bridge operator, and called for its management to resign.

"In a modern and civilized country like Italy we can not afford to see tragic events like this," he said.

"It is not acceptable, and those who made a mistake will have to pay until the end."

The bridge collapsed at the peak of a monster storm earlier this week, after years of talk about its deteriorating condition.

Repair work was carried out in 2016, but plans to rebuild it were abandoned. There will be a criminal inquiry.

For now the focus is on clearing the vast scene - in what is fast becoming a recovery effort.

Earlier, experts warned the Morandi bridge was a disaster waiting to happen years before it collapsed in Genoa on Tuesday, killing dozens.

The death toll in the Italian city rose overnight to 42, with 39 victims identified.

Authorities said the numbers would probably rise with more victims likely to be found in the rubble, with hopes of finding survivors fading.

It has since emerged that warnings had been issued over the bridge – which was built during a post-war construction boom by Società Italiana per Condotte d’Acqua in the 1960s – as far back as 2012.

That year, Giovanni Calvini, then-head of the Genoa branch of the Italian employers organisation Confindustria said it would collapse in "10 years' time".

"This junta mustn't think that the realisation of public works isn't their problem," he said in an interview with the Genoan newspaper Il Secolo XIX.

"Because look, when in 10 years' time the Morandi bridge collapses, and we all get stuck in traffic jams for hours, we will remember the names of the people who said, 'No'."

Mr Calvini was at the time seeking his organisation's backing for new roads.

In 2016, Antonio Brencich of the University of Genoa's engineering faculty also sounded the alarm.

He said the bridge was an "engineering failure" an an interview with broadcaster Primocanale.

He spoke to Italian newspaper La Repubblica after the disastrous collapse, claiming the bridge had been undergoing "constant" maintenance.

"It was affected by serious corrosion problems related to the technology that Morandi himself had patented, but stopped using, and which proved to be disastrous," he said.

Autostrade del Italia, the privately-owned company that had the contract for maintenance of the A10 motorway, said in a statement that "work was underway to shore up the foundations of the viaduct and that, as planned, a car bridge had been installed to allow maintenance activities to be carried out."

Transport Minister Danilo Toninelli, a member of the governing Five Star Movement (M5S), called for the immediate resignation of the company's top management Wednesday.

"First of all the top executives of Autostrade have to resign," he said in a message on Facebook.

"If they can't manage the motorways, then the state will do it."

Mr Toninelli said anybody found to be responsible for the tragedy would "have to pay", a sentiment echoed by other members of the government.

“There cannot be such slaughter without guilt,” said Matteo Salvini, minister of the interior, one of two deputy prime ministers and the most powerful politician in the country.

Prime Minister Giuseppe Conte earlier declared a 12-month state of emergency after a special cabinet meeting in the north-western port city.

About 630 people have been told to leave nearby homes because remaining parts of the bridge might collapse over them, authorities said, adding that the homes will probably have to be knocked down.

About 1,000 rescue workers using sniffer dogs are trying to extract bodies and potentially survivors from the rubble.

"Work will continue for many hours," Regional President Giovanni Toti said, even if there is "feeble hope" of finding people still alive.

However, Mr Salvini said it was "very likely" more victims would be find.

A funeral will be held for the 39 identified victims on Saturday, Mr Conte said in a later Facebook post, adding that it would coincide with a national day of mourning.