Special below-grade concrete placement and waterproofing techniques were developed to speed construction of American Airlines' new baggage handling facilities at Chicago's O'Hare Airport. Essentially a large underground box, the facility encompasses 140,000 square feet, with the lower level located 25 feet below the airline ramp. Due to space limitations and adjacent buried utilities that could not be disturbed, an excavation retention system using soldier piles, tiebacks and soil anchors was chosen to stabilize the perimeter of the excavation during construction. Key elements contributing to rapid building progress were bentonite panels used for waterproofing and a combination of shotcrete and cast-in-place concrete for wall construction.