The NTSB's final report on the Fern Hollow Bridge says the 2022 collapse should have never happened.
NTSB Chair Jennifer Homendy cited extensive corrosion and section loss - details that were formally accepted by the board in an hours-long meeting Wednesday.
She added repeated maintenance and inspection failures over the course of several years played a major role.
“In fact, had contractors for the City of Pittsburgh correctly calculated and accounted for the affects of section loss and other factors in 2014, the Fern Hollow Bridge would have, should have been closed,” said Homendy.
The southwest leg of the bridge, found to have deteriorated significantly finally gave way on January 28, 2022.
Structural engineer Steven Prouty says corrosion and section loss were repeatedly ignored in the years before the bridge fell into Frick Park.
“Maintenance and repair recommendations were repeatedly made to the City of Pittsburgh, however they failed to act on them, this led to progressive deterioration and the structural failure of the bridge,” said Prouty.
Clogged drains also played a role, preventing bridge legs from drying and leading to deterioration.
The NTSB said the time of day and snowy conditions likely prevented a more catastrophic incident.