Large-scale testing of a steel-concrete composite floor system under column loss scenarios was recently conducted by MS candidate Eric Johnson and Prof. Larry Fahnestock. This testing is part of the NSF-supported collaborative research project (CMMI 0969837, CMMI 1000077 and CMMI 1000926) Collaborative Research: Structural Integrity of Steel Gravity Framing Systems, which is being conducted with Prof. Jeffrey Berman (University of Washington) and Prof. Judy Liu (Purdue University). Additional support and structural steel for test specimens were provided by AISC. The test specimen is a three bay by three bay half-scale composite floor system with wide-flange steel beams and girders, corrugated steel deck, shear studs and concrete slab with welded wire fabric. The test specimen was designed to accommodate four column loss scenarios: corner (A4), edge (A2 and C4) and interior (C2). Uniformly distributed loading was approximated by round swimming pools placed in each bay. To date, the corner and edge scenarios have been evaluated. The corner scenario sustained around 60 psf of equivalent uniform load and the edge scenarios sustained around 90 psf of equivalent uniform load. The final test, an interior column loss scenario, will occur in January.