The collapse led to a year-long state of emergency in the Liguria region, extensive analysis of the structural failure,[3] and widely varying assignment of responsibility.
[6][7] The concrete was prestressed only to 10 MPa (1,500 psi),[citation needed] making it susceptible to cracks, water intrusion, and corrosion of the internal steel.
[12] The bridge had been subject to continual restoration work from the 1970s due to an incorrect initial assessment of the effects of creep of the concrete.
[14] In a 1979 report, Morandi himself said "I think [sic] that sooner or later, maybe in a few years, it will be necessary to resort to a treatment consisting of the removal of all traces of rust on the exposure of the reinforcements, to fill the patches, with epoxidic style resins, and finally to cover everything up with elastomers of very high chemical resistance".
[6] In the 1990s, the tendons (the steel wires, cables, and threaded bars, designed to produce the bridge's prestressed concrete) on pillar 11 appeared to be most damaged.
[23][24][25][26][27] The minister of infrastructures and transport in charge until 1 June 2018, Graziano Delrio, was informed multiple times in the Italian parliament during 2016 that the Morandi bridge needed maintenance.
[17] The minutes of a February 2018 government meeting report that resistance and reflectometry measurements indicated an "average" reduction of the cross-section of the tendons of 10 to 20%.
[10][21][36] In 2017, Carmelo Gentile and Antonello Ruccolo of the Polytechnic University of Milan studied the modal frequencies and deformations of the stays of the bridge.
In contrast, with bare tendons, which are relatively under-constrained like the strings in a piano, the effect of prestress is dominant in determining the resonant frequency.
The study highlighted how the traffic volume, with daily queues at peak hours joining the Autostrada Serravalle, produced "an intense degradation of the bridge structure subjected to considerable stress", with the need for continuous maintenance.
[45][failed verification] On 14 August 2018, around 11:36 local time (09:36 UTC), during a torrential rainstorm, the span around pillar 9 of the Ponte Morandi collapsed and the vehicles on it fell into the Polcevera river.
[48][49] The disaster caused a major political controversy about the poor state of infrastructure in Italy and raised wider questions about the condition of bridges across Europe.