A 17m-long 60t concrete beam fell from an overpass onto the Interstate 70 highway in Pennsylvania on Tuesday. Several people suffered minor injuries but no-one was seriously hurt. Engineers from Pennsylvania Department of Transportation and Michael Baker Inc have been examining the 45-year-old structure. Long-term use of de-icing salts and a history of being hit by trucks are among the possible contributory causes being investigated. Seven other concrete beams remain in place. A 4.5km section of the highway was closed for a day but has now been reopened.