June 28, 1983 - At 1:30 am on this day in Greenwich, Connecticut, a 100-foot section of the Mianus River Bridge collapsed and 4 vehicles plunged into the shallow water below. Three people were killed and three others were critically injured.
Had the bridge failed later in the day when traffic on I-95 would be bumper-to-bumper with commuters, casualties would have been much worse.
The main cause of the collapse was significant rust formation on one of the bridge's expansion joints. A crucial pin had become so corroded that the entire weight of the span section was placed on 3 of its corners. The bridge held on for some time before enough fatigue built up and the section finally snapped.
The failure of this bridge served as a grim reminder of the aging infrastructure along the interstate highway system. It also put a spotlight on the lack of adequate inspections performed on bridges.
It would take 6 months to repair the bridge at a cost of over 20 million dollars.