Steve Kroft joins "CBS This Morning" to show a preview of his piece airing Sunday
Bridges, roads, rails and runways are crumbling under our feet. Seven years ago, 13 people died in the dramatic collapse of the I-35W bridge in Minneapolis. Steve Kroft traveled to Pittsburgh to meet with engineers and the former Transportation Secretary Ray LaHood. Kroft joins "CBS This Morning" to show a preview of his piece airing Sunday.
