A new resonant stage is identified in the laboratory during the complex process of soil fluidization by water waves. Massive fluidization failure is consistently observed following internal resonance events inside the silt bed. The weakening effect of this resonance is observed to endure long periods of consolidation. A wave reloading, following such a consolidation period, on a preresonated soil usually results in a recurrence of a similarly massive fluidization failure. Analysis of pore pressure records indicates that the resonance events are localized in space and the associated wave modes are short in wavelengths. It is proposed that these resonant events are a consequence of a strong channeling of the seepage flow within the silt bed. ¿ American Geophysical Union 1994