This is a September, 1948 photograph of the 6th Street Interlocking tower, which controlled the switches and signals at the entrance to Fort Street Union Station.  The tower is on the left.  A new EMD passenger engine is coupled to an outbound C&O/Pere Marquette passenger train.  [Ernie Nowak photo, Charlie Whipp Collection]  Below, a 1966 view of Sixth Street interlocking tower.  [Charles Geletzke, Jr.]