Some parts of the bridge in Genoa, Italy, had not been maintained for 25 years, according to the public prosecutor of the country on Wednesday. A year ago the bridge collapsed, resulting in 43 deaths.
The investigation must show whether the lack of maintenance was the cause of the collapse, the prosecutor says during a press conference.
A memorial service was held for the victims on Wednesday. Their names were read and flowers were laid.
The crucial highway bridge on the west side of the center of Genoa collapsed to a large extent during a storm on 14 August. The bridge was opened in 1967 and is also known as the Morandi bridge, named after the architect Riccardo Morandi.
The Italian public prosecutor is investigating how it could have happened and who might be responsible. This research examines, among other things, the role of Autostrade per l'Italia, the motorway operator.
47Italian police share new images of collapse of Genoa bridge
See also: One year after the mass in Genoa, Italy