NTSB: Bus camera gives information on sequence of Fern Hollow Bridge collapse
PITTSBURGH (KDKA) - The National Transportation Safety Board released an update on its investigation into the Fern Hollow Bridge collapse Thursday, saying video from the Port Authority bus involved gives a better picture of the sequence of events.
The NTSB said the Fern Hollow Bridge experienced a structural failure when the 447-foot span fell 100 feet into Frick Park on Jan. 28, injuring nine people.
The bus' forward-facing camera shows the bridge deck separating at the east expansion joint while the curbside camera shows that at nearly the same time, the west end of the bridge had already fallen off the west abutment, the updated report said.
While the video helps piece together the timeline of the collapse, the NTSB said there's still no evidence of widespread deficiencies with rigid K-frame superstructure types.
The Federal Highway Administration is also helping with the investigation, giving the NTSB resources to evaluate the materials used in building the bridge. The two agencies will do mechanical and chemical testing on samples from parts of each bridge leg and girder sections.
The NTSB is still investigating the collapse with the goal of issuing safety recommendations to prevent similar situations.