  We examine the space-time structure of the particle-emitting sources with
fluctuating initial conditions in smoothed particle hydrodynamics. The two-pion
correlation functions of single events for the sources exhibit event-by-event
fluctuations. The large event-by-event fluctuations and wide distributions of
the error-inverse-weighted fluctuations between the HBT correlation functions
of single and mixed events are important features for the sources with the
fluctuating initial conditions. The root-mean-square of the weighted
fluctuations is a signal to detect the inhomogeneity of the systems produced in
high energy heavy ion collisions.
