Search teams in Italy are working around the clock hoping to find more survivors after a giant highway bridge collapsed Tuesday, killing at least 39 people.
The death toll in the Italian city rose overnight to 42, with 39 victims identified.
The Office has opened an investigation into possible negligent homicide.
There has been anger and disbelief in Italy that such a vital structure could have simply given way.
Italy's biggest toll-road operator came under heavy stock-market attack on Thursday after Rome criticized it for a deadly bridge collapse this week, moving to revoke its concession and accusing it of failing to ensure the viaduct's safety.
The bridge's condition - and its ability to sustain large increases in both the intensity and weight of traffic over the years - have been a focus of public debate since Tuesday's collapse, when an 80-metre span gave way at lunchtime as cars and trucks streamed across it.
The collapse of the Morandi bridge in Genoa killed at least 38 people and injured 15, five of them critically.
It's not yet clear what went wrong with the bridge.
The firm, which said the bridge had been undergoing maintenance work, however, released a statement refuting accusations of underfunding of motorway infrastructure.
Meanwhile, Autostrade said the bridge was constantly monitored beyond legal requirements.
He also the government would inspect the structure of ageing bridges and tunnels across the country with a view to launching a programme of remedial works if required.
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The Morandi Bridge, inaugurated in 1967, was just over three-quarters of a mile long, with the longest section between supports measuring 200 yards.
Genoa is a port city located in the Liguria region of Italy.
Some major repairs were also done to the bridge in the 1990s.
One construction expert, Antonio Brencich at the University of Genoa, had previously called the bridge "a failure of engineering".
Stefano Marigliani, a senior executive at Autostrade in charge of the part of the toll road network linking the French and Italian Rivieras that includes the bridge, told the Financial Times that the structure "was monitored constantly beyond legal requirements" and that there was "no reason to consider it unsafe".
Prime Minister Giuseppe Conte said "all infrastructure" across the country needed to be double-checked.
Italian Prime Minister Conte declared a 12-month state of emergency.
There will be a national day of mourning on Saturday to coincide with the funerals of victims.
On Tuesday engineering website "Ingegneri.info" called it "a tragedy waiting to happen".
They included families in their cars, people going to work, and people going on holiday.
"If there are European constraints preventing us from spending money to secure the schools attended by our children or the highways our workers are traveling on, we will put the safety of Italians ahead of everyone and everything", he wrote on Twitter. "We even found a family - a father, mother and a small child who were together, in a vehicle, and unfortunately the three of them were dead".
One of the most compelling testimonies came from Davide Capello, 33, a former goalkeeper for Serie A side Cagliari.