PITTSBURGH (AP) — Federal regulators are about to announce what they believe caused a bridge to collapse in Pittsburgh more than two years ago, sending vehicles plummeting into a ravine and injuring several people. The National Transportation Safety Board is expected to vote Wednesday on the results of its investigation into the January 2022 collapse of the Forbes Avenue bridge over Fern Hollow Creek. The bridge’s collapse dropped a bus and four cars about 100 feet on the day President Joe Biden visited Pittsburgh to promote spending on infrastructure. A new bridge at the site opened to traffic in December 2022.