Large-scale floor system tests concluded a collaborative research project that studied the structural integrity of steel gravity framing systems composed of steel beams and girders with composite concrete slab on steel deck. Simple steel beam-column connection tests were conducted at the University of Washington, steel-concrete composite slab tests were conducted at Purdue University, and complete floor system tests were conducted at the University of Illinois at Urbana-Champaign. The complete floor system tests evaluate gravity systems subjected to severe demands consistent with column loss scenarios, complementing the previously-completed component tests. The floor system tests were conducted at half-scale on a three-bay square configuration that considers interior, exterior and corner column loss scenarios. The three-bay by three-bay configuration was chosen so that multiple tests could be conducted using one structure. For each test, the bays adjacent to the removed column were incrementally loaded with distributed load until the floor could not support more load. These experiments provide valuable data to validate existing numerical models, to identify critical limit states, and to determine system capacities under various column loss scenarios.