Reduction in soil volume due to inundation under a constant total stress is a phenomenon referred to as collapse. Collapse is exhibited by soils during a change of state from an unsaturated to a saturated condition. Several researchers have postulated various theories to explain collapse behavior. Recent published research has attempted to explain the collapse phenomenon using theories of unsaturated soil mechanics. However, the theoretical explanations require further verification by experimental data. A simple experimental procedure is suggested in this paper to measure changes in matric suction and soil volume during inundation. The suggested measurements provide experimental data that can be used to verify the applicability of the unsaturated soil mechanics theories to collapsible soil behavior. Typical test results from this experimental program indicate that collapsible soil behavior can be explained using unsaturated soil mechanics theories.