Opened in 1971, Neponset River Bridge carries Morrissey Boulevard traffic over Neponset River. The superstructure consists of steel plate girders and cover-plated steel stringers supporting a 7.5 in. thick reinforced concrete deck. The girders span 108 ft, with shorter spans in the curved portion of the bridge. Nineteen twin hammerhead piers and five twin wall piers support the superstructure. In a routine inspection of the Neponset River Bridge, Metropolitan District Commission personnel found cracks in several of the piers. A subsequent engineering study found that the cracks were due to over-stresses in the flexural steel and abrupt termination of flexural steel in a tension zone.