[ad_1] The authorities in Pittsburgh closed McKees Rocks Bridge as a precaution after several barges broke loose on the Ohio River late Friday. There is a risk that the barges could come into contact with the “substructure” of the bridge, the McKees Rocks Police Department said in a statement early Saturday confirming the closure. The department said it closed the bridge because it was “not willing to take the risk.” The bridge opened in 1931 and stretches more than a mile across the Ohio River. As part of the Blue…