Renzo Piano, the Italian architect who designed the Shard in London, says he is readily available to help rebuild the Morandi bridge, which collapsed this month in his home city of Genoa, killing 43 people.

Piano, who grew up in a family of builders in the port city, said the sadness over the lives lost was “like a shadow that stays with you” but that any reconstruction could become a “positive moment of unity and cooperation”.

“I’ve already said I would be happy [to be involved] because that’s my mission,” he told the Observer. “I’m also a senator for life [in the Italian parliament] and so it is one of my duties to respond to such a disaster in some way.”

The architect, who lives in Paris but has an office in Genoa, said that negativity arising from the political rancour since the tragedy could be counteracted by collaboration on a rebuild. While it was too early to talk about the design of a new bridge, he said, any future structure must be a statement of “real pride and values”.

“One thing for sure is that it must be beautiful – not in the sense of cosmetics but in conveying a message of truth and pride,” he said.

“It must be a place where people can recognise the tragedy in some way, while also providing a great entrance to the city. All this must be done without any sign of rhetoric – that would be the worst trap. But I think we will stay away [from that] and instead try to express real pride and values. That is what Genoa deserves.” He added: “Genoa is reluctant to spread emotion – it’s quite introspective and timid, but the strength is inside, like a retained energy. So it’s not a city that is screaming and shouting, but that doesn’t mean it doesn’t need help – and I will try to help.”

Facebook Twitter Pinterest The partially collapsed Morandi bridge, in Genoa, 19 August 2018. Photograph: Luca Zennaro/EPA

Piano, 80, was at a meeting in Geneva on 14 August when he heard about the collapse of the bridge, designed by the civil engineer Riccardo Morandi and opened in 1967, when Italy was still in the wave of enthusiastic postwar reconstruction and such projects expressed hope for the future.

“Morandi was a great engineer for sure, and he made something audacious, clever and brave but, of course, very fragile,” said Piano. “Fragile in the sense of a beauty that is fragile – it’s not a criticism. The bridge demanded an extremely high level of attention during its lifespan.”

Piano said that the collapse of the arterial road, which connected east and west Genoa, and the Lombardy and Piedmont regions with Liguria and French border, had split the port city in two. “A bridge is a symbol and should never fall, because when a bridge falls, walls go up. So it’s not only physical but metaphorical – walls are bad, we should not build walls, but bridges are good, they make connections.”

Determining the cause of the bridge’s collapse is now in the hands of a Genoa court. Morandi warned in 1979 that the bridge would require constant maintenance to remove rust caused by sea air and pollution from a nearby steel plant. Other engineering experts had long warned of structural issues and the people of Genoa had worried about the safety of the bridge for decades.

“I understand there [could be] many different causes, but one is probably the implicit fragility,” said Piano.

“When you make a complex building you may be very clever but then you need clever people to follow the life of the structure, people who really know the science.”

The offices of Autostrade, the highways operator responsible for maintaining the bridge, were raided last week after the Italian government launched proceedings to revoke its concessions.

The populist administration, which came to power in early June, rounded on the privately owned company for alleged poor maintenance. The firm, which has agreed to provide a €500m (£450m) relief fund and vowed to rebuild the structure, claimed that the bridge had been maintained every quarter.

Piano, who is considered one of the world’s greatest architects, designed the Pompidou centre in Paris alongside his friend Richard Rogers. He speaks fondly of his childhood in Genoa, recalling that he spent most of his school holidays on construction sites.

“It was like growing up in the circus, and you become an acrobat by necessity.”