Firefighters reported hearing noises from the eastern pillar on Sunday night and again on Monday morning, Ansa news agency reported.
Fears of another collapse led them to call for checks on the stability of what remains of the A10 motorway bridge. If the structure is found to present a concrete danger, local authorities said they were prepared to order its demolition.
A handful of residents evacuated from homes underneath the bridge had been allowed to return to collect possessions, but were once more ordered to clear the site out of fears for their safety. Emergency vehicles were also instructed to stay out of the so-called “red zone” around the bridge.
After rescue teams announced that all those reported missing in the disaster had now been accounted for, the investigation continues into what caused part of the bridge to give way suddenly on Tuesday afternoon, killing 43 people.
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The collapse may have been due to “a series of causes” rather than the failure of a single support, investigators told the press on Monday. While the sequence of events is not yet clear, it appears the bridge was out of joint before it fell, according to Roberto Ferrazza, head of the Ministry of Infrastructure's inspection committee.
Investigators are also looking into whether a heavy overhead crane on the bridge could have caused the structure to buckle, sources told Ansa.
Italy's new government has blamed the tragedy on poor maintenance of the 50-year-old bridge, for which ministers have pointed the finger at private motorway operator Autostrade per l'Italia, as well as previous administrations and the European Union.
After threatening to revoke Autostrade's contract to manage nearly half of the country's main road network, Rome said it was considering renationalizing all Italy's motorways.
Infrastructure Minister Danilo Toninelli has commented that renationalization would be “convenient” and the coalition government is “studying” the possibility, Interior Minister Matteo Salvini told Rai 3 TV on Monday, while adding that he was in favour of a “healthy co-presence of public and private, but the public must be in charge”.
Meanwhile several people remain in hospital and hundreds more have been displaced from their homes after Tuesday's collapse. The first 11 households were preparing to move into substitute accommodation on Monday, while some 40 others will receive new apartments in the coming weeks.
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Photo: Valery Hache/AFP