On 29th June 1890, a catastrophic flood of the Stabina torrent and its side valleys swept away and destroyed the ancient two-arched stone bridge that connected thebridge area to the centre of the village, wiping out forever the numerous iron forges in the Pornera area, upstream and in the Ponte area, where iron had been worked for centuries, producing nails, blades and weapons, and where up to 220 "zochi" or stumps had been reached, indicating the number of workplaces.
From that June 29th, the forges were no longer open and the Ponte district remained isolated.
On 20th November 1891, engineer Natale Calvi (1826-1892) from Piazza Brembana, drew up a project for the "construction of a metal truss bridge weighing 6,763 kg, with a span of 27 metres for use as a bridge". On 26th January, the mayor Tobia Valcher awarded the contract to the local firm Luigi Bagini. The work, made of hot-bolted steel and prepared according to precise calculations of resistance, tension and expansion, still speaks to us today of the expertise of the great engineer Natale Calvi, who in 1857 had designed the extension of the parish church of Cassiglio and who from 1863 to 1868 in Puglia had designed and directed the construction of the Bari-Taranto and Bari-Barletta railway networks. This latest work and artefact of his is a significant sign in the Valley of advancing technological innovation. It certainly does not compete in size with the contemporary Eiffel Tower or the large steel bridge in Paderno, but it tells us that the Industrial Revolution in Italy had also arrived in Cassiglio, once a major centre for ironworking. The work was tested on 30th December 1892 by engineer Giacomo Calvetti of Piazza Brembana, when Natale Calvi had recently left us.