PITTSBURGH — As far back as 2014, the state of Pennsylvania found enough problems with the Fern Hollow Bridge over Frick Park that it said inspections should be launched every year instead of every 24 months, a state official told the Post-Gazette on Monday.
Four years later, Pittsburgh officials found that a rusting and detached X-shaped bracing on the bridge had become a “safety concern” and decided to remove it, a document obtained by the Post-Gazette shows, leaving steel cables as support in their place — a decision at least one expert said was questionable.
The city also turned up other needed repairs, but they were not viewed as “as imminent hazards” and were pushed off to future years but do not appear to have been done.
Exactly what other repairs were identified is not known.
But in the wake of the bridge’s collapse Friday that injured 10 people and left seven vehicles crushed in the rubble, the decision to remove the brace, rely on steel cables for support and apparently leave some repairs undone may become critical factors in the investigation now underway by the National Transportation Safety Board.
So far, neither the state nor the city will release details of past inspections to provide a fuller history of the bridge and potentially what went wrong in the morning hours last week.
And the firms involved in the most recent inspection of the bridge, just months ago in September, would not provide any insight into what was turned up during that key inspection.
The inspector for the September visit to the bridge was Gannett Fleming Inc., an international firm with headquarters in Camp Hill and an office in Green Tree.
“Gannett Fleming was part of the inspection team for the Fern Hollow Bridge in 2020 and 2021,” the company said in an email to the Post-Gazette.
“We are grateful there were no serious injuries and commend the Pittsburgh Department of Public Safety and all first responders who assisted with the evacuations. While it is too early to know the cause of the collapse, we have committed to make all personnel and information available to the appropriate agencies to assist in a thorough investigation.”
Gannett Fleming became the inspector for the bridge after winning a larger contract with three other firms to carry out the reviews on numerous bridges for the city.
One of those other three firms, Larson Design Group, said in an email that while the company was part of the group that bid to carry out inspections, “In this case, Gannett Fleming, a company with a century of experience in global infrastructure, performed all inspections on the Fern Hollow Bridge as the engineer of record in 2020 and 2021.”
Even before the state ordered the annual inspections in 2014, conditions had been deteriorating for at least seven years, according to a federal database.
In 1999, an inspection found that all three elements of the bridge were found to be in “fair” condition or better.
By 2009, the conditions had declined, although the bridge wasn’t labeled poor until a 2011 inspection when the superstructure — which supports the deck where vehicles drive across — was found to be in poor condition.
Then, at some point before 2014, the X-bracing under the west side of the bridge had deteriorated so badly that the city decided to install wire cable to add additional support.
That breakdown would become a trouble spot in the ensuing years and would challenge experts over the safety of the span.
The city had conducted a “stability” analysis and found that the original cross-bracing steel supports were “non-functional” and it was relying on the wire cables to be “tight and fully engaged.”
During an inspection in September 2013, experts found the cable bracing on the west side was now critical to the bridge’s support because “the bracing on the frame legs have a number of large holes and [their] connection to the frame legs exhibit 100% section loss. More holes have formed in the frame leg webs,” according to a city document.
But the 2013 inspection found that even the steel cables had begun to have problems and were “loose and move freely, lacking tension.”
The city hired Michael Facchiano Contracting, of Pittsburgh, to tighten the cables for $8,651.97, which it did in 2014.
Facchiano also removed the steel beam for $43,794.66 in early 2019, leaving the wire cable system as the replacement support.
Calls and emails to Facchiano on Monday were not returned.
Hota GangaRao, an engineering professor and director of the Constructed Facilities Center at West Virginia University, said that in general, bracing is a critical element for a bridge’s superstructure.
Using cables is not nearly as effective as steel beams because the beams handle long-distance weight distribution and compression, but cables don’t help with compression from weight on the structure.
“Any amount of cross-bracing is going to be beneficial,” GangaRao said. “Bracing is always a help.
“[Using cables instead] could be an issue. A beam is always a better thing. Without question, a plate and a beam are a better option,” he added.
By 2019, Fern Hollow Bridge’s deck was found to be poor as well. The bottom portion of the bridge, known as the substructure, remained in “satisfactory” shape through last year’s inspection — meaning that it only showed minor deterioration.
Last year’s inspection also showed the same two elements of the bridge were labeled poor.
It wasn’t just the findings during inspections that drew officials’ attention to the span over Frick Park.
Local residents walking by the 49-year-old structure voiced concerns, with 311 data showing four alerts relating to the condition of the bridge from 2016 to 2019 — including the man who took a now-viral photo in 2018 of the rusted-through X cross-beam and posted it on Twitter, alerting the city’s 311 service.
In time, two issues emerged that would underscore the growing concerns.
One was a recommendation from inspectors that examinations of the bridge increase to once a year, according to the Pennsylvania Department of Transportation, which oversees inspections for all jurisdictions.
That coincided with the weight limit on the bridge being reduced from 36 tons to 26 tons, said PennDOT spokeswoman Alexis Campbell — a cap that’s typically imposed when concerns are raised about a deteriorating structure.
Campbell described the bridge as a “K-frame” structure — a design where weight is placed on single supports that have no secondary backup.
PennDOT said there are five other bridges across the state with the same type of design as Fern Hollow. The department is recommending the bridge owners take some action as a result of the collapse, but Campbell said she didn’t know exactly what they were told to do.
The other five bridges, including the nearby ramp from Beechwood Boulevard to the Parkway East in Squirrel Hill, are all rated fair or better.
Allegheny County Executive Rich Fitzgerald said the day of the collapse that he hoped a review would take place on how bridges are assessed.
"I think it'll also show a spotlight on how often bridge inspections are done, weight limits, all the type of things that we know need to be done, and because there hasn't been money over the years, we've deferred a lot of things that need to be done."
Because of the lockdown on detailed inspection reports, it’s difficult to assess what finally went wrong from the last inspection of Fern Hollow in September.
Summary reports about some of the reviews are available online, but Campbell said the law bans the release of the full documents, which include inspection notes about specific problems on bridges, because that information could identify vulnerabilities that could be used by terrorists, she said.
Additionally, the NTSB has instructed agencies to refer all media questions about the incident to the board. Investigators expect their report will take 12 to 18 months to complete.
Fern Hollow Bridge is one of roughly 176 bridges in Allegheny County that are labeled poor, and one of about 30 in Pittsburgh.
The rating only means that the deterioration of at least one structural element has advanced, not that the bridge is in serious danger of collapse.
While the scores in the final inspection remained the same, it’s clear a toll had been taken on the bridge.
Four months later, it collapsed.
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