June 28: The Mianus River Bridge Over I-95 Collapses


Early in the morning of June 28th, 1983, at around 1:30 am, a 100-foot span of Interstate 95 in Greenwich collapsed into the Mianus River in one of the most infamous American bridge disasters of the 20th century.   Three people died and three more were seriously injured as a car and two tractor-trailers careened over the edge. The death toll could have been exponentially higher if the collapse had happened during rush hour, as that stretch of I-95 was then (and remains now) one of the most heavily-traveled highway corridors in the United States.

Subsequent investigations found that the immediate cause of the Mianus River bridge collapse was two corroded support pins; however, years of deferred maintenance and systematic neglect were the true culprit.  People were shocked to discover that the bridge was only 25 years old and had apparently passed a routine DOT inspection only nine months before.  In the days leading up to the collapse, local residents who lived near the bridge had complained about an ominous increase in strange noises and vibrations coming from the bridge, but no action was taken.

For months, tens of thousands of vehicles who traveled I-95 daily had to be diverted onto Route 1 in Greenwich, clogging up local roads throughout the region as crews worked to get the bridge repaired.  In July, the temporarily-repaired bridge was reopened to light vehicle traffic; buses and trucks would have to wait until full repairs were completed in September.

The Mianus River bridge collapse spurred drastic changes in how highway bridges were constructed; builders were thereafter required to incorporate multiple redundancies into their designs so that the failure of one single feature (e.g. a support pin) would not cause a collapse.  However, after the Great Recession of 2008 tightened state and federal spending, transportation advocates continue to point to the Mianus bridge collapse as an ominous warning of the consequences of too much deferred maintenance on American roadways.

1983 footage of the Mianus River bridge collapse from Connecticut news affiliate WTNH.

Further Reading

Karen Frederick and Anne Young, “Mianus River Bridge Collapses,” connecticuthistory.org

Bill Cummings, “Then and Now: I-95’s Mianus River Bridge Collapse,Greenwich Times

Martin B. Cassidy, “Lessons of Mianus River Bridge Not Yet Learned,” Stamford Advocate