The Chicago Federal Plaza in Chicago’s Loop district includes the John C. Kluczynski Federal Building and Loop Station Post Office, both designed by Ludwig Mies van der Rohe. The plaza is used often for community activities, such as protest demonstrations and a weekly farmers market. The General Services Administration (GSA) carried out a complete rehabilitation of the plaza in the early 2010s. GSA personnel observed displacement of the plaza’s granite pavers, particularly at drain locations, and became concerned about tripping hazards. SGH investigated the cause of the pavers’ movement and helped the project team evaluate remedial options.