Pcol writes: "The New York Times is reporting that investigators of the bridge that collapsed in Minneapolis last week have found what may be a design flaw in the gusset plates that connect girders and raises the possibility that the bridge was structurally deficient from the day it opened. Although officials said they were still working to confirm the design flaw, in making their suspicion public, they were signaling that they considered it a potentially crucial discovery. Federal authorities said there was added stress on the gusset plates from the weight of construction equipment and nearly 100 tons of gravel on the bridge, where maintenance work was proceeding when the collapse occurred. A construction crew had removed part of the deck with 45-pound jackhammers, in preparation for replacing the two-inch top layer, and that may have also altered the stresses on the bridge, some experts said. If the engineers who designed the bridge in 1964 miscalculated the loads and used metal parts that were too weak for the job, it would recast the national debate that has emerged, about whether enough attention has been paid to maintenance."